Exhibit 1

EXECUTION COPY

SIRIUS SATELLITE RADIO INC.

40,000,000 Shares of Common Stock

Underwriting Agreement

As of September 15, 2005

J.P. Morgan Securities Inc.

277 Park Avenue

New York, New York 10172

Ladies and Gentlemen:

Apollo Investment Fund IV, L.P. and Apollo Overseas Partners IV, L.P. (each a “Selling Stockholder”, and together, the “Selling Stockholders”) propose to sell to J.P. Morgan Securities Inc. (the “Underwriter”) an aggregate of 40,000,000 shares of common stock, par value $0.001 per share (the “Stock”), of Sirius Satellite Radio Inc., a Delaware corporation (the “Company”) (such shares being referred to herein as the “Shares”). The number of Shares to be sold by each Selling Stockholder is set forth on Schedule 1.

The Company and the Selling Stockholders hereby confirm their agreement with the Underwriter concerning the purchase and sale of the Shares, as follows:

1. Registration Statement. The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Securities Act”), a registration statement on Form S-3 (File No. 333-104406), including a prospectus, relating to the Shares, which registration statement was declared effective by the Commission on May 20, 2003. Such registration statement, as amended at the time it became effective, including the information deemed pursuant to Rule 430A under the Securities Act to be part of the registration statement at the time of its effectiveness, is referred to herein as the “Registration Statement”; and as used herein, and the term “Prospectus” means the prospectus (including any prospectus supplement) in the form first used to confirm sales of the Shares. Any reference in this Agreement to the Registration Statement or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act, as of the effective date of the Registration Statement or the date of the Prospectus, as the case may be, and any reference to “amend”, “amendment” or “supplement” with respect to the Registration Statement or the Prospectus shall be deemed to refer to and include any documents filed after such date under the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Exchange Act”) that are deemed to be incorporated by reference therein. Capitalized terms used but not defined herein shall have the meanings given to such terms in the Registration Statement and the Prospectus.

2. Purchase of the Shares by the Underwriter. (a) The Selling Stockholders agree to sell the Shares to the Underwriter as provided in this Agreement, and the Underwriter, on the basis of the representations, warranties and agreements set forth herein and subject to the conditions set forth herein, agrees to purchase the Shares from the Selling Stockholders at a purchase price per share of $7.046.

(b) The Company and the Selling Stockholders understand that the Underwriter intends to make a public offering of the Shares and initially to offer the Shares on the terms set forth in the Prospectus. The Selling Stockholders acknowledge and agree that the Underwriter may offer and sell Shares to or through any affiliate of an Underwriter and that any such affiliate may offer and sell Shares purchased by it to or through any Underwriter.

(c) Payment for the Shares shall be made by wire transfer in immediately available funds to the accounts specified by the Selling Stockholders to the Underwriter, at the offices of Cravath, Swaine & Moore LLP at 10:00 a.m., New York City time, on Thursday, September 22, 2005, or at such other time or place on the same or such other date, not later than the fifth business day thereafter, as the Selling Stockholders and the Underwriter may agree upon in writing. The time and date of such payment are referred to herein as the “Closing Date”.

Payment for the Shares shall be made against delivery to the Underwriter of the Shares in definitive form registered in such names and in such denominations as the Underwriter shall request in writing not later than two full business days prior to the Closing Date, with any transfer taxes payable in connection with the sale of the Shares duly paid by the Selling Stockholders. The certificates for the Shares will be made available for inspection and packaging by the Underwriter at the office of J.P. Morgan Securities Inc. set forth above not later than 1:00 p.m., New York City time, on the business day prior to the Closing Date.

(d) Each of the Company and the Selling Stockholders acknowledges and agrees that the Underwriter is acting solely in the capacity of an arm’s-length contractual counterparty to the Company and the Selling Stockholders with respect to the offering of Shares contemplated hereby (including in connection with determining the terms of the offering) and not as a financial advisor or a fiduciary to, or an agent of, the Company, the Selling Stockholders or any other person. Additionally, the Underwriter is not advising the Company, the Selling Stockholders or any other person as to any legal, tax, investment, accounting or regulatory matters in any jurisdiction. The Company and the Selling Stockholders shall consult with their own advisors concerning such matters and shall be responsible for making their own independent investigation and appraisal of the transactions contemplated hereby, and the Underwriter shall have no responsibility or liability to the Company or the Selling Stockholders with respect thereto. Any review by the Underwriter of the Company, the transactions contemplated hereby or other matters relating to such transactions will be performed solely for the benefit of the Underwriter and shall not be on behalf of the Company or the Selling Stockholders.

3. Representations and Warranties of the Company. The Company represents and warrants to the Underwriter and the Selling Stockholders that:

(a) Registration Statement and Prospectus. The Registration Statement has been declared effective by the Commission, and no order suspending the effectiveness of the Registration Statement has been issued by the Commission and no proceeding for that purpose has been initiated or threatened by the Commission; as of the applicable effective date of the Registration Statement and any amendment thereto, the Registration Statement complied and will comply in all material respects with the Securities Act, and did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading; and as of the applicable filing date of the Prospectus and any amendment or supplement thereto and as of the Closing Date, the Prospectus will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company makes no representation or warranty with respect to any statements or omissions made in reliance upon and in conformity with information relating to the Underwriter furnished to the Company in writing by the Underwriter expressly for use in the Registration Statement and the Prospectus or any amendment or supplement thereto.

(b) Incorporated Documents. The documents incorporated by reference in the Prospectus, when they become effective or were filed with the Commission, as the case may be, conformed in all material respects to the requirements of the Securities Act or the Exchange Act, as applicable, and none of such documents contained any untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; and any further documents so filed and incorporated by reference in the Prospectus, when such documents become effective or are filed with the Commission, as the case may be, will conform in all material respects to the requirements of the Securities Act or the Exchange Act, as applicable, and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(c) Financial Statements. The financial statements and the related notes thereto included or incorporated by reference in the Registration Statement and the Prospectus comply in all material respects with the applicable requirements of the Securities Act and the Exchange Act, as applicable, and present fairly the financial position of the Company and its consolidated subsidiaries as of the dates indicated and the results of their operations and the changes in their cash flows for the periods specified; such financial statements have been prepared in conformity with United States generally accepted accounting principles (“GAAP”) applied on a consistent basis throughout the periods covered thereby, and the supporting schedules included or incorporated by reference in the Registration Statement present fairly the information required to be stated therein; and the other historical financial information included or incorporated by reference in the Registration Statement and the Prospectus has been derived from the accounting records of the Company and its subsidiaries and presents fairly in all material respects the information shown thereby.

(d) No Material Adverse Change. Since the date of the most recent financial statements of the Company included or incorporated by reference in the Registration Statement

and the Prospectus, (i) there has not been any change in the capital stock or long-term debt of the Company or the Subsidiary (as defined below), or any dividend or distribution of any kind declared, set aside for payment, paid or made by the Company on any class of capital stock, or any material adverse change in the condition (financial or otherwise), earnings, business affairs or business prospects of the Company and the Subsidiary, taken as a whole; (ii) neither the Company nor the Subsidiary has entered into any transaction or agreement that is material to the Company and the Subsidiary, taken as a whole, or incurred any liability or obligation, direct or contingent, that is material to the Company and the Subsidiary, taken as a whole; and (iii) neither the Company nor the Subsidiary has sustained any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor disturbance or dispute or any action, order or decree of any court or arbitrator or governmental or regulatory authority, except in each case as otherwise disclosed in the Registration Statement and the Prospectus.

(e) Organization and Good Standing. The Company and the Subsidiary have been duly organized and are validly existing and in good standing under the laws of their respective jurisdictions of organization, are duly qualified to do business and are in good standing in each jurisdiction in which their respective ownership or lease of property or the conduct of their respective businesses requires such qualification, and have all power and authority necessary to own or hold their respective properties and to conduct the businesses in which they are engaged, except where the failure to be so qualified or have such power or authority would not, individually or in the aggregate, have a material adverse effect on the condition (financial or otherwise), earnings, business affairs or business prospects of the Company and the Subsidiary, taken as a whole (a “Material Adverse Effect”). The subsidiary listed in Schedule 2 to this Agreement is the only “significant subsidiary” of the Company, as such term is defined in Rule 1-02 of Regulation S-X promulgated under the Securities Act, and is referred to herein as the “Subsidiary”.

(f) Capitalization. The Company has an authorized capitalization as set forth in the Prospectus. All the outstanding shares of capital stock of the Company (including the Shares to be sold by the Selling Stockholder) have been duly and validly authorized and issued and are fully paid and non-assessable and are not subject to any pre-emptive or similar rights; except as described in or expressly contemplated by the Prospectus, there are no outstanding rights (including, without limitation, pre-emptive rights), warrants or options to acquire, or instruments convertible into or exchangeable for, any shares of capital stock or other equity interest in the Company or any of its subsidiaries, or any contract, commitment, agreement, understanding or arrangement of any kind relating to the issuance of any capital stock of the Company or any such subsidiary, any such convertible or exchangeable securities or any such rights, warrants or options; the capital stock of the Company conforms in all material respects to the description thereof contained in the Registration Statement and the Prospectus; and all the outstanding shares of capital stock or other equity interests of each subsidiary of the Company have been duly and validly authorized and issued, are fully paid and non-assessable and are owned directly or indirectly by the Company, free and clear of any lien, charge, encumbrance, security interest, restriction on voting or transfer or any other claim of any third party.

(g) Due Authorization. The Company has full right, power and authority to execute and deliver this Agreement and to perform its obligations hereunder and thereunder; and all actions required to be taken for the due and proper authorization, execution and delivery of this Agreement and the consummation of the transactions contemplated hereby have been duly and validly taken.

(h) Underwriting Agreement. This Agreement has been duly authorized, executed and delivered by the Company.

(i) Descriptions of this Agreement. The description of this Agreement contained in the Registration Statement and the Prospectus conforms in all material respects to the terms of this Agreement.

(j) Listing. The issued and outstanding Stock, including the Shares, has been listed for quotation on The NASDAQ National Market.

(k) No Violation or Default. Neither the Company nor the Subsidiary is (i) in violation of its charter or by-laws or similar organizational documents, (ii) in default, and no event has occurred that, with notice or lapse of time or both, would constitute such a default, in the due performance or observance of any term, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or the Subsidiary is a party or by which the Company or the Subsidiary is bound or to which any of the property or assets of the Company or the Subsidiary is subject, or (iii) in violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority, except, in the case of clauses (ii) and (iii) above, for any such default or violation that would not, individually or in the aggregate, have a Material Adverse Effect.

(l) No Conflicts. The execution, delivery and performance by the Company of this Agreement and compliance by the Company with the terms hereof and the consummation of the transactions contemplated hereby will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or the Subsidiary pursuant to, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or the Subsidiary is a party or by which the Company or the Subsidiary is bound or to which any of the property or assets of the Company or the Subsidiary is subject, (ii) result in any violation of the provisions of the charter or by-laws or similar organizational documents of the Company or the Subsidiary or (iii) result in the violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority, except, in the case of clauses (i) and (iii) above, for any such conflict, breach or violation that would not, individually or in the aggregate, have a Material Adverse Effect.

(m) No Consents Required. No consent, approval, authorization, order, registration or qualification of or with any court or arbitrator or governmental or regulatory authority is required for the execution, delivery and performance by the Company of this Agreement and compliance by the Company with the terms hereof and the consummation of the transactions contemplated

hereby, except for the registration of the Shares under the Securities Act and such consents, approvals, authorizations, orders and registrations or qualifications as may be required under applicable state securities laws in connection with the purchase and distribution of the Shares by the Underwriter.

(n) Legal Proceedings. Except as described in the Prospectus, there are no legal, governmental or regulatory investigations, actions, suits or proceedings pending to which the Company or the Subsidiary is or may be a party or to which any property of the Company or the Subsidiary is or may be the subject that, individually or in the aggregate, if determined adversely to the Company or the Subsidiary, could reasonably be expected to have a Material Adverse Effect; and no such investigations, actions, suits or proceedings are, to the knowledge of the Company, threatened or contemplated by any governmental or regulatory authority or threatened by others.

(o) Independent Accountants. Ernst & Young LLP, who have certified certain financial statements of the Company and its subsidiaries, is an independent registered public accounting firm with respect to the Company and its subsidiaries within the meaning of the Securities Act and the applicable rules and regulations adopted by the Commission and the Public Company Accounting Oversight Board.

(p) Title to Real and Personal Property. The Company and the Subsidiary have good and marketable title in fee simple to, or have valid rights to lease or otherwise use, all items of real and personal property that are material to the respective businesses of the Company and the Subsidiary, in each case free and clear of all liens, encumbrances, claims and defects and imperfections of title except those that (i) do not materially interfere with the use made and proposed to be made of such property by the Company and the Subsidiary or (ii) could not reasonably be expected, individually or in the aggregate, to have a Material Adverse Effect.

(q) Title to Intellectual Property. The Company and the Subsidiary own or possess, or can acquire on reasonable terms, adequate rights to use all material patents, patent applications, trademarks, service marks, trade names, trademark registrations, service mark registrations, copyrights, licenses and know-how (including trade secrets and other unpatented and/or unpatentable proprietary or confidential information, systems or procedures) necessary for the conduct of their respective businesses; and, to the knowledge of the Company, the conduct of their respective businesses will not conflict in any material respect with any such rights of others, and the Company and the Subsidiary have not received any notice of any claim of infringement of or conflict with any such rights of others, except, in each case, where the failure to own or possess such rights or where any such conflict or infringement would not, individually or in the aggregate, have a Material Adverse Effect.

(r) Investment Company Act. Neither the Company nor the Subsidiary is an “investment company” or an entity “controlled” by an “investment company” within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder.

(s) Taxes. The Company and the Subsidiary have paid all federal, state, local and foreign taxes and filed all tax returns required to be paid or filed through the date hereof, except

for taxes being contested in good faith for which reserves in accordance with GAAP have been provided and except where the failure to pay or file would not, individually or in the aggregate, be reasonably expected to have a Material Adverse Effect; and except as otherwise disclosed in the Prospectus, there is no tax deficiency that has been, or could reasonably be expected to be, asserted against the Company or the Subsidiary or any of their respective properties or assets, except for any deficiency that would not, individually or in the aggregate, be reasonably expected to have a Material Adverse Effect.

(t) Licenses and Permits. Except as described in the Prospectus, the Company and the Subsidiary possess all licenses, certificates, permits and other authorizations (including, without limitation, all permits required for the operation of the business of the Company and the Subsidiary by the FCC and each state and local authority that regulates the activities of the Company) (collectively, “Governmental Licenses”) issued by, and have made all declarations and filings with, the appropriate federal, state, local or foreign governmental or regulatory authorities that are necessary for the ownership or lease of their respective properties or the conduct of their respective businesses as described in the Registration Statement and the Prospectus, except where the failure to possess or make the same would not, individually or in the aggregate, have a Material Adverse Effect; and except as described in the Prospectus, neither the Company nor the Subsidiary have received notice of any revocation or modification of any such Governmental Licenses or have any reason to believe that any such Governmental Licenses will not be renewed in the ordinary course, except where the notice of any revocation or modification would not, individually or in the aggregate, have a Material Adverse Effect.

(u) No Labor Disputes. No labor disturbance by or dispute with employees of the Company or the Subsidiary exists or, to the knowledge of the Company, is contemplated or threatened that would reasonably be expected to have a Material Adverse Effect.

(v) Compliance with Environmental Laws. The Company and the Subsidiary (i) are in compliance with any and all applicable federal, state, local and foreign laws, rules, regulations, decisions and orders relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes, pollutants or contaminants (collectively, “Environmental Laws”), (ii) have received and are in compliance with all permits, licenses or other approvals required of them under applicable Environmental Laws to conduct their respective businesses, and (iii) have not received notice of any actual or potential liability for the investigation or remediation of any disposal or release of hazardous or toxic substances or wastes, pollutants or contaminants, except in any such case for any such failure to comply, or failure to receive required permits, licenses or approvals, or liability, as would not, individually or in the aggregate, have a Material Adverse Effect.

(w) Compliance with ERISA. Except as would not, individually or in the aggregate, have a Material Adverse Effect, (i) each employee benefit plan, within the meaning of Section 3(3) of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), that is maintained, administered or contributed to by the Company or the Subsidiary for employees or former employees of the Company and the Subsidiary (each, a “Plan”) has been maintained in compliance with its terms and the requirements of any applicable statutes, orders, rules and regulations, including but not limited to ERISA and the Internal Revenue Code of

1986, as amended (the “Code”); (ii) no prohibited transaction, within the meaning of Section 406 of ERISA or Section 4975 of the Code, has occurred with respect to any such Plan, excluding transactions effected pursuant to a statutory or administrative exemption; and (iii) for each such Plan that is subject to the funding rules of Section 412 of the Code or Section 302 of ERISA, no “accumulated funding deficiency” as defined in Section 412 of the Code has been incurred, whether or not waived.

(x) Accounting Controls. The Company and the Subsidiary maintain and will maintain disclosure controls and procedures (as defined in Rule 13a-14 of the Exchange Act) designed to ensure that information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported in accordance with the Exchange Act and the rules and regulations thereunder. The Company and the Subsidiary have carried out and will carry out evaluations, under the supervision and with the participation of the Company’s management, of the effectiveness of the design and operation of the Company’s disclosure controls and procedures in accordance with Rule 13a-15 of the Exchange Act.

(y) No Restrictions on Subsidiaries. No subsidiary of the Company is currently prohibited, directly or indirectly, under any agreement or other instrument to which it is a party or is subject, from paying any dividends to the Company, from making any other distribution on such subsidiary’s capital stock, from repaying to the Company any loans or advances to such subsidiary from the Company or from transferring any of such subsidiary’s properties or assets to the Company or any other subsidiary of the Company.

(z) No Broker’s Fees. Neither the Company nor the Subsidiary is a party to any contract, agreement or understanding with any person (other than this Agreement) that would give rise to a valid claim against any of them or the Underwriter for a brokerage commission, finder’s fee or like payment in connection with the offering and sale of the Shares.

(aa) No Registration Rights. No person has the right to require the Company or any of its subsidiaries to register any securities for sale under the Securities Act by reason of the filing of the Registration Statement with the Commission or, to the best knowledge of the Company, the sale of the Shares by the Selling Stockholder hereunder.

(bb) No Stabilization. The Company has not taken, directly or indirectly, any action designed to, or that could reasonably be expected to, cause or result in any stabilization or manipulation of the price of the Shares.

(cc) Forward-Looking Statements. No forward-looking statement (within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act) contained in the Registration Statement and the Prospectus has been made or reaffirmed without a reasonable basis or has been disclosed other than in good faith.

4. Representations and Warranties of the Selling Stockholders. Each of the Selling Stockholders severally and not jointly represents and warrants to the Underwriter and the Company that:

(a) Required Consents; Authority. All consents, approvals, authorizations and orders necessary for the execution and delivery by such Selling Stockholder of this Agreement, and for the sale and delivery of the Shares hereunder, have been obtained; such Selling Stockholder has full right, power and authority to enter into this Agreement and to sell, assign, transfer and deliver the Shares; and this Agreement has been duly authorized, executed and delivered by such Selling Stockholder.

(b) No Conflicts. The execution, delivery and performance by such Selling Stockholder of this Agreement, the sale of the Shares and compliance by such Selling Stockholder with the terms hereof and the consummation by such Selling Stockholder of the transactions contemplated hereby will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of such Selling Stockholder pursuant to, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which such Selling Stockholder is a party or by which such Selling Stockholder is bound or to which any of the property or assets of such Selling Stockholder is subject, (ii) result in any violation of the provisions of the charter or by-laws or similar organizational documents of such Selling Stockholder or (iii) result in the violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory agency having jurisdiction over such Selling Stockholder or the property or the assets of such Selling Stockholder.

(c) Title to Shares. Such Selling Stockholder has good and valid title to the Shares to be sold on the Closing Date hereunder, free and clear of all liens, encumbrances, equities or adverse claims; such Selling Stockholder will have, immediately prior to the Closing Date, good and valid title to the Shares to be sold at the Closing Date, free and clear of all liens, encumbrances, equities or adverse claims; and, upon delivery of such Shares and payment therefor pursuant hereto, good and valid title to such Shares, free and clear of all liens, encumbrances, equities or adverse claims, will pass to the Underwriter who has purchased such Shares without notice of an adverse claim.

(d) No Stabilization. Such Selling Stockholder has not taken and will not take, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in any stabilization or manipulation of the price of the Shares.

(e) Registration Statement and Prospectus. As of the applicable filing date of the Prospectus and any amendment or supplement thereto and as of the Closing Date, the Prospectus will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the foregoing representation and warranty is made only with respect to statements and omissions made in reliance upon and in conformity with information relating to the Selling Stockholder furnished to the Company in writing by the Selling Stockholder expressly for use in the Registration Statement or the Prospectus or any amendment or supplement thereto.

(f) Material Information. As of the date hereof and as of the Closing Date, the sale of such Shares sold by such Selling Stockholder is not and will not be prompted by any material information concerning the Company that is not set forth in the Registration Statement or the Prospectus.

5. Further Agreements of the Company. The Company covenants and agrees with the Underwriter that:

(a) Prospectus. The Company will file the final Prospectus with the Commission within the time periods specified by Rule 424(b) and Rule 430A under the Securities Act and will file promptly all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of the Prospectus and for so long as the delivery of a prospectus is required in connection with the offering or sale of the Shares; and the Company will furnish copies of the Prospectus to the Underwriter in New York City prior to 10:00 a.m., New York City time, on the business day next succeeding the date of this Agreement in such quantities as the Underwriter may reasonably request.

(b) Delivery of Copies. The Company will deliver to the Underwriter during the Prospectus Delivery Period (as defined below) as many copies of the Prospectus (including all amendments and supplements thereto and documents incorporated by reference therein) as the Underwriter may reasonably request. As used herein, the term “Prospectus Delivery Period” means such period of time after the first date of the public offering of the Shares as in the opinion of counsel for the Underwriter a prospectus relating to the Shares is required by law to be delivered in connection with sales of the Shares by the Underwriter or any dealer.

(c) Amendments or Supplements. Before filing any amendment or supplement to the Registration Statement or the Prospectus, the Company will furnish to the Underwriter and counsel for the Underwriter a copy of the proposed amendment or supplement for review, and will not file any such proposed amendment or supplement to which the Underwriter reasonably objects.

(d) Notice to the Underwriter. The Company will advise the Underwriter promptly, and confirm such advice in writing, (i) when any amendment to the Registration Statement has been filed or becomes effective; (ii) when any supplement or any amendment to the Prospectus has been filed; (iii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or the receipt of any comments from the Commission relating to the Registration Statement or any other request by the Commission for any additional information; (iv) of the issuance by the Commission of any order suspending the effectiveness of the Registration Statement or preventing or suspending the use of the Prospectus or the initiation or threatening of any proceeding for that purpose; (v) of the occurrence of any event within the Prospectus Delivery Period as a result of which the Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, not misleading; and (vi) of the receipt by the Company of any notice with respect to any suspension of the

qualification of the Shares for offer and sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose; and the Company will use its reasonable best efforts to prevent the issuance of any such order suspending the effectiveness of the Registration Statement, preventing or suspending the use of the Prospectus or suspending any such qualification of the Shares and, if any such order is issued, will obtain as soon as possible the withdrawal thereof.

(e) Ongoing Compliance of the Prospectus. If during the Prospectus Delivery Period (i) any event shall occur or condition shall exist as a result of which the Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, not misleading or (ii) it is necessary to amend or supplement the Prospectus to comply with law, the Company will immediately notify the Underwriter thereof and forthwith prepare and, subject to paragraph (c) above, file with the Commission and furnish to the Underwriter and to such dealers as the Underwriter may designate, such amendments or supplements to the Prospectus as may be necessary so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, be misleading or so that the Prospectus will comply with law.

(f) Blue Sky Compliance. The Company will qualify the Shares for offer and sale under the securities or Blue Sky laws of such jurisdictions as the Underwriter shall reasonably request and will continue such qualifications in effect so long as required for distribution of the Shares; provided that the Company shall not be required to (i) qualify as a foreign corporation or other entity or as a dealer in securities in any such jurisdiction where it would not otherwise be required to so qualify, (ii) file any general consent to service of process in any such jurisdiction or (iii) subject itself to taxation in any such jurisdiction if it is not otherwise so subject.

(g) Earning Statement. The Company will make generally available to its security holders and the Underwriter as soon as practicable an earning statement that satisfies the provisions of Section 11(a) of the Securities Act and Rule 158 of the Commission promulgated thereunder covering a period of at least twelve months beginning with the first fiscal quarter of the Company occurring after the “effective date” (as defined in Rule 158) of the Registration Statement.

(h) Clear Market. For a period of 30 days after the Closing Date, the Company will not (i) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of, directly or indirectly, any shares of Stock or any securities convertible into or exercisable or exchangeable for Stock or (ii) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the Stock, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of Stock or such other securities, in cash or otherwise, without the prior written consent of the Underwriter, other than any shares of Stock of the Company issued upon the exercise of options granted under existing employee stock option plans. Notwithstanding the foregoing, if (A) during the last 17 days of the 30-day restricted period, the Company issues an earnings release or material news or a material event relating to the Company occurs, or (B) prior

to the expiration of the 30-day restricted period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the 30-day period, the restrictions imposed by this Agreement shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event.

(i) No Stabilization. The Company will not take, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in any stabilization or manipulation of the price of the Shares.

6. Further Agreements of the Selling Stockholders. Each Selling Stockholder covenants and agrees with the Underwriter that:

(a) Clear Market. For a period of 30 days after the Closing Date, such Selling Stockholder will not (i) offer, pledge, announce the intention to sell, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase or otherwise transfer or dispose of, directly or indirectly, any shares of Stock or any securities convertible into or exercisable or exchangeable for Stock or (ii) enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the Stock, whether any such transaction described in clause (i) or (ii) above is to be settled by delivery of Stock or such other securities, in cash or otherwise, or (iii) make any demand for or exercise any right with respect to the registration of any shares of Stock or any security convertible into or exercisable or exchangeable for Stock without the prior written consent of the Underwriter, in each case other than the Shares to be sold by such Selling Stockholder hereunder. Notwithstanding the foregoing, if (A) during the last 17 days of the 30-day restricted period, the Company issues an earnings release or material news or a material event relating to the Company occurs, or (B) prior to the expiration of the 30-day restricted period, the Company announces that it will release earnings results during the 16-day period beginning on the last day of the 30-day period, the restrictions imposed by this Agreement shall continue to apply until the expiration of the 18-day period beginning on the issuance of the earnings release or the occurrence of the material news or material event.

(b) Tax Form. Such Selling Stockholder will deliver to the Underwriter prior to or at the Closing Date a properly completed and executed United States Treasury Department Form W-9 (or other applicable form or statement specified by the Treasury Department regulations in lieu thereof) in order to facilitate the Underwriter’s documentation of its compliance with the reporting and withholding provisions of the Tax Equity and Fiscal Responsibility Act of 1982 with respect to the transactions herein contemplated.

7. Conditions of Underwriter’s Obligations. The obligation of the Underwriter to purchase Shares on the Closing Date as provided herein is subject to the performance by the Company and the Selling Stockholders of their respective covenants and other obligations hereunder and to the following additional conditions:

(a) No Stop Order. No order suspending the effectiveness of the Registration Statement shall be in effect, and no proceeding for such purpose shall be pending before or threatened by the Commission; the Prospectus shall have been timely filed with the Commission

under the Securities Act and in accordance with Section 5(a) hereof; and all requests by the Commission for additional information shall have been complied with to the reasonable satisfaction of the Underwriter.

(b) Representations and Warranties. The respective representations and warranties of the Company and the Selling Stockholders contained herein shall be true and correct on the date hereof and on and as of the Closing Date; and the statements of the Company and its officers and of the Selling Stockholders made in any certificate delivered pursuant to this Agreement shall be true and correct on and as of the Closing Date.

(c) No Downgrade. Subsequent to the execution and delivery of this Agreement and prior to the Closing Date, (i) no downgrading shall have occurred in the rating accorded any securities or preferred stock issued or guaranteed by the Company by any “nationally recognized statistical rating organization”, as such term is defined by the Commission for purposes of Rule 436(g)(2) under the Securities Act; and (ii) no such organization shall have publicly announced that it has under surveillance or review, or has changed its outlook with respect to, its rating of any securities or preferred stock issued or guaranteed by the Company (other than an announcement with positive implications of a possible upgrading).

(d) No Material Adverse Change. Subsequent to the execution and delivery of this Agreement and prior to the Closing Date, no event or condition of a type described in Section 3(d) hereof shall have occurred or shall exist, which event or condition is not described in the Prospectus (excluding any amendment or supplement thereto) and the effect of which in the judgment of the Underwriter makes it impracticable or inadvisable to proceed with the offering, sale or delivery of the Shares on the Closing Date on the terms and in the manner contemplated by this Agreement and the Prospectus.

(e) Officer’s Certificate. The Underwriter shall have received on and as of the Closing Date a certificate (i) of an executive officer of the Company who has specific knowledge of the Company’s financial matters and is satisfactory to the Underwriter (A) confirming that such officer has carefully reviewed the Registration Statement and the Prospectus and, to the best knowledge of such officer, the representation of the Company set forth in Section 3(a) hereof is true and correct, (B) confirming that the other representations and warranties of the Company in this Agreement are true and correct and that the Company has complied with all agreements and satisfied all conditions on its part to be performed or satisfied hereunder at or prior to the Closing Date and (C) to the effect set forth in paragraphs (a), (c) and (d) above, and (ii) of the Selling Stockholders, in form and substance reasonably satisfactory to the Underwriter, (A) confirming that the representation of such Selling Stockholder set forth in Section 4(e) hereof is true and correct and (B) confirming that the other representations and warranties of such Selling Stockholder in this Agreement are true and correct and that such Selling Stockholder has complied with all agreements and satisfied all conditions on its part to be performed or satisfied hereunder at or prior to such Closing Date.

(f) Comfort Letter. On the Closing Date, Ernst & Young LLP shall have furnished to the Underwriter, at the request of the Company, a letter, dated the Closing Date and addressed to the Underwriter, in form and substance reasonably satisfactory to the Underwriter, containing

statements and information of the type customarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained or incorporated by reference in the Registration Statement and the Prospectus; provided that such letter shall use a “cut-off” date no more than three business days prior to the Closing Date.

(g) Opinion of the General Counsel for the Company. Patrick L. Donnelly, Executive Vice President, General Counsel and Secretary for the Company, shall have furnished to the Underwriter, at the request of the Company, his written opinion, dated the Closing Date and addressed to the Underwriter, in form and substance reasonably satisfactory to the Underwriter.

(h) Opinion of Counsel for the Company. Simpson Thacher & Bartlett LLP, counsel for the Company, shall have furnished to the Underwriter, at the request of the Company, their written opinion, dated the Closing Date and addressed to the Underwriter, in form and substance reasonably satisfactory to the Underwriter.

(i) Opinion of Regulatory Counsel for the Company. Wiley, Rein & Fielding LLP, regulatory counsel for the Company, shall have furnished to the Underwriter, at the request of the Company, their written opinion, dated the Closing Date and addressed to the Underwriter, in form and substance reasonably satisfactory to the Underwriter.

(j) Opinions of Counsel for the Selling Stockholders. Morgan, Lewis & Bockius LLP, counsel for the Selling Stockholders, shall have furnished to the Underwriter, at the request of the Selling Stockholders, their written opinion, dated the Closing Date and addressed to the Underwriter, in form and substance reasonably satisfactory to the Underwriter. The Underwriter shall also have received an opinion of Cayman Islands counsel satisfactory to the Underwriter regarding the execution, delivery and performance of this Agreement by Apollo Overseas Partners IV, L.P.

(k) Opinion of Counsel for the Underwriter. The Underwriter shall have received on and as of the Closing Date an opinion of Cravath, Swaine & Moore LLP, counsel for the Underwriter, with respect to such matters as the Underwriter may reasonably request, and such counsel shall have received such documents and information as they may reasonably request to enable them to pass upon such matters.

(l) No Legal Impediment to Sale. No action shall have been taken and no statute, rule, regulation or order shall have been enacted, adopted or issued by any federal, state or foreign governmental or regulatory authority that would, as of the Closing Date, prevent the sale of the Shares; and no injunction or order of any federal, state or foreign court shall have been issued that would, as of the Closing Date, prevent the sale of the Shares.

(m) Good Standing. The Underwriter shall have received on and as of the Closing Date satisfactory evidence of the good standing of the Company and the Subsidiary in their respective jurisdictions of organization and their good standing in such other jurisdictions as the Underwriter may reasonably request, in each case in writing or any standard form of telecommunication, from the appropriate governmental authorities of such jurisdictions.

(n) Additional Documents. On or prior to the Closing Date, the Company shall have furnished to the Underwriter and the Selling Stockholders such further certificates and documents as the Underwriter may reasonably request.

All opinions, letters, certificates and evidence mentioned above or elsewhere in this Agreement shall be deemed to be in compliance with the provisions hereof only if they are in form and substance reasonably satisfactory to counsel for the Underwriter.

8. Indemnification and Contribution.

(a) Indemnification of the Underwriter by the Company. The Company agrees to indemnify and hold harmless the Underwriter, its affiliates, directors and officers and each person, if any, who controls the Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act, from and against any and all losses, claims, damages and liabilities (including, without limitation, legal fees and other expenses reasonably incurred in connection with any suit, action or proceeding or any claim asserted, as such fees and expenses are incurred), joint or several, that arise out of, or are based upon, any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or the Prospectus (or any amendment or supplement thereto) or any omission or alleged omission to state therein a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, except insofar as such losses, claims, damages or liabilities arise out of, or are based upon, any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with any information relating to the Underwriter furnished to the Company by the Underwriter expressly for use therein, it being understood and agreed that the only such information furnished by the Underwriter consists of the information described as such in paragraph (c) below.

(b) Indemnification of the Underwriter by the Selling Stockholders. Subject to the last sentence of this Section 8(b), each of the Selling Stockholders hereunder agrees to severally and not jointly indemnify and hold harmless the Underwriter, its affiliates, directors and officers and each person, if any, who controls the Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act, from and against any and all losses, claims, damages and liabilities (including, without limitation, the legal fees and other expenses reasonably incurred in connection with any suit, action or proceeding or any claim asserted, as such fees and expenses are incurred), joint or several, that arise out of, or are based upon, any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement or the Prospectus (or any amendment or supplement thereto) or omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement, or omission or alleged omission, was made in reliance upon and in conformity with any information relating to such Selling Stockholder furnished to the Company by such Selling Stockholder expressly for use therein. Each Selling Stockholder’s payment obligation under this Section 8(b) is limited to an amount equal to the proceeds received by such Selling Stockholder (before deducting expenses) from the sale of Shares by it pursuant to this Agreement.

(c) Indemnification of the Company and the Selling Stockholders. The Underwriter agrees to indemnify and hold harmless the Company, its directors, its officers who signed the Registration Statement and each person, if any, who controls the Company within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act and the Selling Stockholders to the same extent as the indemnity set forth in paragraph (a) above, but only with respect to any losses, claims, damages or liabilities that arise out of, or are based upon, any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with any information relating to the Underwriter furnished to the Company in writing by the Underwriter expressly for use in the Registration Statement and the Prospectus (or any amendment or supplement thereto), it being understood and agreed that the only such information furnished by the Underwriter consists of the following information in the Prospectus furnished on behalf of the Underwriter: the last paragraph set out on the cover page and the third, eighth, ninth and eleventh paragraphs under the caption “Underwriting”.

(d) Notice and Procedures. If any suit, action, proceeding (including any governmental or regulatory investigation), claim or demand shall be brought or asserted against any person in respect of which indemnification may be sought pursuant to the preceding paragraphs of this Section 8, such person (the “Indemnified Person”) shall promptly notify the person against whom such indemnification may be sought (the “Indemnifying Person”) in writing; provided that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have under this Section 8 except to the extent that it has been materially prejudiced (through the forfeiture of substantive rights or defenses) by such failure; and provided, further, that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have to an Indemnified Person otherwise than under this Section 8. If any such proceeding shall be brought or asserted against an Indemnified Person and it shall have notified the Indemnifying Person thereof, the Indemnifying Person shall retain counsel reasonably satisfactory to the Indemnified Person to represent the Indemnified Person and any others entitled to indemnification pursuant to this Section 8 that the Indemnifying Person may designate in such proceeding and shall pay the reasonable fees and expenses of such counsel related to such proceeding, as incurred. In any such proceeding, any Indemnified Person shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such Indemnified Person unless (i) the Indemnifying Person and the Indemnified Person shall have mutually agreed to the contrary; (ii) the Indemnifying Person has failed within a reasonable time to retain counsel reasonably satisfactory to the Indemnified Person; (iii) the Indemnified Person shall have reasonably concluded that there may be legal defenses available to it that are different from or in addition to those available to the Indemnifying Person; or (iv) the named parties in any such proceeding (including any impleaded parties) include both the Indemnifying Person and the Indemnified Person and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them. It is understood and agreed that the Indemnifying Person shall not, in connection with any proceeding or related proceeding in the same jurisdiction, be liable for the fees and expenses of more than one separate firm (in addition to any local counsel) for all Indemnified Persons, and that all such fees and expenses shall be reimbursed as they are incurred. Any such separate firm for the Underwriter, its affiliates, directors and officers and any control persons of the Underwriter shall be designated in writing by J.P. Morgan Securities Inc., any such separate firm for the Company, its directors, its officers who signed the Registration Statement and any control persons of the

Company shall be designated in writing by the Company and any such separate firm for the Selling Stockholders shall be designated in writing by the Selling Stockholders. The Indemnifying Person shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the Indemnifying Person agrees to indemnify each Indemnified Person from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an Indemnified Person shall have requested that an Indemnifying Person reimburse the Indemnified Person for fees and expenses of counsel as contemplated by this paragraph, the Indemnifying Person shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 30 days after receipt by the Indemnifying Person of such request and (ii) the Indemnifying Person shall not have reimbursed the Indemnified Person in accordance with such request prior to the date of such settlement. No Indemnifying Person shall, without the written consent of the Indemnified Person, effect any settlement of any pending or threatened proceeding in respect of which any Indemnified Person is or could have been a party and indemnification could have been sought hereunder by such Indemnified Person, unless such settlement (x) includes an unconditional release of such Indemnified Person, in form and substance reasonably satisfactory to such Indemnified Person, from all liability on claims that are the subject matter of such proceeding and (y) does not include any statement as to or any admission of fault, culpability or a failure to act by or on behalf of any Indemnified Person.

(e) Contribution. If the indemnification provided for in paragraphs (a), (b) and (c) above is unavailable to an Indemnified Person or insufficient in respect of any losses, claims, damages or liabilities referred to therein, then each Indemnifying Person under such paragraph, in lieu of indemnifying such Indemnified Person thereunder, shall contribute to the amount paid or payable by such Indemnified Person as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the relative benefits received by the Company and the Selling Stockholders, on the one hand, and the Underwriter, on the other, from the offering of the Shares or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) but also the relative fault of the Company and the Selling Stockholders, on the one hand, and the Underwriter, on the other, in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, as well as any other relevant equitable considerations. The relative benefits received by the Company and the Selling Stockholders, on the one hand, and the Underwriter, on the other, in connection with the offering of the Shares shall be deemed to be in the same respective proportions as the net proceeds (before deducting expenses) received by the Company and the Selling Stockholders from the sale of the Shares and the total underwriting discounts and commissions received by the Underwriter in connection therewith, as provided in this Agreement, bear to the aggregate offering price of the Shares. The relative fault of the Company, the Selling Stockholders and the Underwriter shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company, the Selling Stockholders or by the Underwriter and the parties’ intent and relative, knowledge, access to information and opportunity to correct or prevent such statement or omission.

(f) Limitation on Liability. The Company, the Selling Stockholders and the Underwriter agree that it would not be just or equitable if contribution pursuant to this Section 8 were determined by pro rata allocation or by any other method of allocation that does not take account of the equitable considerations referred to in paragraph (e) above. The amount paid or payable by an Indemnified Person as a result of the losses, claims, damages and liabilities referred to in paragraph (e) above shall be deemed to include, subject to the limitations set forth above, any legal or other expenses reasonably incurred by such Indemnified Person in connection with any such action or claim. Notwithstanding the provisions of this Section 8, in no event shall the Underwriter be required to contribute any amount in excess of the amount by which the total underwriting discounts and commissions received by the Underwriter with respect to the offering of the Shares exceeds the amount of any damages that the Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation.

(g) Non-Exclusive Remedies. The remedies provided for in this Section 8 are not exclusive and shall not limit any rights or remedies that may otherwise be available to any Indemnified Person at law or in equity.

9. Termination. This Agreement may be terminated in the absolute discretion of the Underwriter, by notice to the Company and the Selling Stockholders, if after the execution and delivery of this Agreement and prior to the Closing Date (i) trading generally shall have been suspended or materially limited on or by any of the New York Stock Exchange, the National Association of Securities Dealers, Inc. or in any over-the-counter market; (ii) trading of any securities issued or guaranteed by the Company shall have been suspended on any exchange or in any over-the-counter market; (iii) a general moratorium on commercial banking activities shall have been declared by federal or New York State authorities or a material disruption in commercial banking or securities settlement or clearance services in the United States; or (iv) there shall have occurred any outbreak or escalation of hostilities or any change in financial markets or any calamity or crisis, either within or outside the United States, that, in the judgment of the Underwriter, is material and adverse and makes it impracticable or inadvisable to proceed with the offering, sale or delivery of the Shares on the Closing Date on the terms and in the manner contemplated by this Agreement and the Prospectus.

10. Payment of Expenses. (a) Whether or not the transactions contemplated by this Agreement are consummated or this Agreement is terminated, the Company agrees to pay or cause to be paid all costs and expenses incident to the performance of its obligations hereunder, including, without limitation, (i) the costs incident to the preparation, printing and filing under the Securities Act of the Registration Statement and the Prospectus (including all exhibits, amendments and supplements thereto) and the distribution thereof to the Underwriter; (ii) the costs of reproducing and distributing this Agreement and the documentation related hereto; (iii) the fees and expenses incurred in connection with the registration or qualification and determination of eligibility for investment of the Shares under the laws of such jurisdictions as the Underwriter may designate and the preparation, printing and distribution of a Blue Sky Memorandum (including the related fees and expenses of counsel for the Underwriter); (iv) the fees and

expenses of the Company’s counsel and independent accountants in connection with this Agreement; (v) the costs and charges of any transfer agent or any registrar; and (vi) the costs related to the transfer and delivery of the Shares to the Underwriter, including any transfer or other taxes payable thereon.

(b) It is understood that the Underwriter will pay all of its costs and expenses, including fees and expenses of its counsel, transfer taxes payable upon resale of any of the Shares by it and any advertising expenses incurred in connection with any of the resale offers it may make.

(c) If (i) this Agreement is terminated pursuant to Section 9, (ii) the Selling Stockholders for any reason fail to tender the Shares for delivery to the Underwriter or (iii) the Underwriter declines to purchase the Shares for any reason permitted under this Agreement, the Company agrees to reimburse the Underwriter for all out-of-pocket costs and expenses (including the reasonable fees and expenses of its counsel) reasonably incurred by the Underwriter in connection with this Agreement and the offering contemplated hereby.

11. Persons Entitled to Benefit of Agreement. This Agreement shall inure to the benefit of and be binding upon the parties hereto and their respective successors and any controlling persons referred to herein, and the affiliates, officers and directors of the Underwriter referred to in Section 8 hereof. Nothing in this Agreement is intended or shall be construed to give any other person any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision contained herein. No purchaser of Shares from the Underwriter shall be deemed to be a successor merely by reason of such purchase.

12. Survival. The respective indemnities, rights of contribution, representations, warranties and agreements of the Company, the Selling Stockholders and the Underwriter contained in this Agreement or made by or on behalf of the Company, the Selling Stockholders or the Underwriter pursuant to this Agreement or any certificate delivered pursuant hereto shall survive the delivery of and payment for the Shares and shall remain in full force and effect, regardless of any termination of this Agreement or any investigation made by or on behalf of the Company, the Selling Stockholders or the Underwriter.

13. Certain Defined Terms. For purposes of this Agreement, (a) except where otherwise expressly provided, the term “affiliate” has the meaning set forth in Rule 405 under the Securities Act; (b) the term “business day” means any day other than a day on which banks are permitted or required to be closed in New York City; and (c) the term “subsidiary” has the meaning set forth in Rule 405 under the Securities Act.

14. Miscellaneous. (a) Notices. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted and confirmed by any standard form of telecommunication. Notices to the Underwriter shall be given to it at J.P. Morgan Securities Inc., 277 Park Avenue, New York, New York 10172 (fax: (212) 622-8358); Attention: Syndicate Desk. Notices to the Company shall be given to it at Sirius Satellite Radio Inc., 1221 Avenue of the Americas, 37th Floor, New York, NY 10020 (fax: (212) 584-5353); Attention: Patrick L. Donnelly, Executive Vice President, General Counsel and Secretary. Notices to the Selling Stockholders shall be given to Apollo Advisors IV, L.P. at Two

Manhattanville Road, Purchase, New York 10577, with a copy to Morgan, Lewis and Bockius LLP, 1111 Pennsylvania Avenue, N.W., Washington, D.C. 20004, Attention: David A. Sirignaro.

(b) Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the State of New York.

(c) Counterparts. This Agreement may be signed in counterparts (which may include counterparts delivered by any standard form of telecommunication), each of which shall be an original and all of which together shall constitute one and the same instrument.

(d) Amendments or Waivers. No amendment or waiver of any provision of this Agreement, nor any consent or approval to any departure therefrom, shall in any event be effective unless the same shall be in writing and signed by the parties hereto.

(e) Entire Agreement. This Agreement, together with any contemporaneous written agreements and any prior written agreements (to the extent not expressly superseded by this Agreement) that relate to the offering of the Shares, represents the entire agreement between the Company and the Selling Stockholders, on the one hand, and the Underwriter, on the other, with respect to the preparation of the Prospectus, the conduct of the offering and the purchase and sale of the Shares.

(f) Headings. The headings herein are included for convenience of reference only and are not intended to be part of, or to affect the meaning or interpretation of, this Agreement.

If the foregoing is in accordance with your understanding, please indicate your acceptance of this Agreement by signing in the space provided below.

Very truly yours,

SIRIUS SATELLITE RADIO INC.

	By

		Name: David Frear
		Title: Executive Vice President and Chief
				Financial Officer


APOLLO INVESTMENT FUND IV, L.P.,

	By	APOLLO ADVISORS IV, L.P.
		Its General Partner,

	By	APOLLO CAPITAL MANAGEMENT IV, INC.
		Its General Partner,

		by
			Name: Michael D. Weiner
			Title: Vice President


APOLLO OVERSEAS PARTNERS IV, L.P.,

	By	APOLLO ADVISORS IV, L.P.
		Its Managing General Partner,

	By	APOLLO CAPITAL MANAGEMENT IV, INC.
		Its General Partner,

		by
			Name: Michael D. Weiner
			Title: Vice President

Schedule 1

Selling Stockholder		Number of Shares to be sold

Apollo Investment Fund IV, L.P.		37,963,527

Apollo Overseas Partners IV, L.P.		2,036,473

J.P. MORGAN SECURITIES INC.


By
Authorized Signatory