REGISTRATION RIGHTS AGREEMENT

Exhibit 4.2

XM SATELLITE RADIO HOLDINGS INC.

1.75% CONVERTIBLE SENIOR NOTES DUE 2009

REGISTRATION RIGHTS AGREEMENT

November 23, 2004

BEAR, STEARNS & CO. INC.

383 Madison Avenue

New York, New York 10179

Ladies and Gentlemen:

XM Satellite Radio Holdings Inc., a Delaware corporation (the “Company”), proposes to issue and sell to the initial purchaser named in the purchase agreement (the “Initial Purchaser”), upon the terms set forth in such purchase agreement dated November 18, 2004 (the “Purchase Agreement”), its 1.75% Convertible Senior Notes due 2009 (the “Securities”). As an inducement to the Initial Purchaser to enter into the Purchase Agreement and in satisfaction of a condition to the obligations of the Initial Purchaser thereunder, the Company agrees with the Initial Purchaser for the benefit of Holders (as defined herein) from time to time of the Registrable Securities (as defined herein) as follows:

Capitalized terms used herein without definition shall have the meanings ascribed to them in the Purchase Agreement. As used in this Agreement, the following defined terms shall have the following meanings:

“ Additional Interest ” has the meaning assigned thereto in Section 7(a) hereof.

“ Additional Shares ” has the meaning assigned thereto in Section 7(a) hereof.

“ Affiliate ” of any specified person means any other person which, directly or indirectly, is in control of, is controlled by, or is under common control with such specified person. For purposes of this definition, control of a person means the power, direct or indirect, to direct or cause the direction of the management and policies of such person whether by contract or otherwise; and the terms “controlling” and “controlled” have meanings correlative to the foregoing.

“ Applicable Amount ” means, (i) with respect to the Securities, the principal amount of the Securities and (ii) with respect to shares of Common Stock issued upon conversion of the Securities pursuant to the Indenture, the principal amount of Securities that would then be convertible into such number of shares.

“ Business Day ” means each Monday, Tuesday, Wednesday, Thursday and Friday that is not a day on which banking institutions in The City of New York are authorized or obligated by law or executive order to close.

“ Commission ” means the United States Securities and Exchange Commission, or any other federal agency at the time administering the Exchange Act or the Securities Act, whichever is the relevant statute for the particular purpose.

“ Common Stock ” means the Company’s class A common stock, par value $0.01 per share.

“ DTC ” means The Depository Trust Company.

“ Effectiveness Period ” has the meaning assigned thereto in Section 2(b)(i) hereof.

“ Effective Time ” means the time at which the Commission declares any Shelf Registration Statement effective or at which any Shelf Registration Statement otherwise becomes effective.

“ Exchange Act ” means the United States Securities Exchange Act of 1934, as amended.

“ Holder ” means any person that is the record owner of Registrable Securities (and includes any person that has a beneficial interest in any Registrable Security in book-entry form).

“ Indenture ” means the Indenture, dated as of November 23, 2004, between the Company and The Bank of New York, pursuant to which the Securities are to be issued, and as amended and supplemented from time to time in accordance with its terms.

“ Issue Date ” means the first date of original issuance of the Securities.

“ Majority of Holders ” means Holders holding over 50% of the aggregate principal amount of Registrable Securities outstanding.

“ Notice and Questionnaire ” means a Notice of Registration Statement and Selling Securityholder Notice and Questionnaire substantially in the form of Appendix A hereto.

“ Notice Holder ” has the meaning assigned thereto in Section 3(a)(i) hereof.

The term “ person ” means an individual, partnership, limited liability company, corporation, trust or unincorporated organization, or a government or agency or political subdivision thereof.

“ Prospectus ” means the prospectus included in any Shelf Registration Statement, as amended or supplemented by any prospectus supplement with respect to the terms of the offering of any portion of the Registrable Securities covered by any Shelf Registration Statement and by all other amendments and supplements to such prospectus, including all material incorporated by reference in such prospectus and all documents filed after the date of such prospectus by the Company under the Exchange Act and incorporated by reference therein.

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“ Registrable Securities ” means all or any portion of the Securities issued from time to time under the Indenture in registered form and the shares of Common Stock issuable upon conversion of such Securities until the earliest of: (x) the date on which such security has been registered under the Securities Act and disposed of pursuant to an effective registration statement, (y) the date that is two years after the later of (1) the last date of original issuance of the Securities and (2) the last date that the Company or any of its Affiliates was the owner of such Securities (or any predecessor thereto), or such shorter period of time as permitted by Rule 144(k) (or any successor rule or regulation) under the Securities Act or any successor provisions thereunder or (z) its sale to the public pursuant to Rule 144 (or any successor rule or regulation) under the Securities Act.

“ Registration Default ” has the meaning assigned thereto in Section 7(a) hereof.

“ Securities Act ” means the United States Securities Act of 1933, as amended.

“ Shelf Registration ” means a registration effected pursuant to Section 2 hereof.

“ Shelf Registration Statement ” means a “shelf” registration statement filed under the Securities Act providing for the registration of, and the sale on a continuous or delayed basis by the Holders of, all of the Registrable Securities pursuant to Rule 415 under the Securities Act and/or any similar rule that may be adopted by the Commission, filed by the Company pursuant to the provisions of Section 2 of this Agreement, including the Prospectus contained therein, any amendments and supplements to such registration statement, including post-effective amendments, and all exhibits and all material incorporated by reference in such registration statement, and any additional “shelf” registration statements filed under the Securities Act to permit the registration and sale of Registrable Securities pursuant to Section 3(a)(ii) hereof.

“ Suspension Period ” has the meaning assigned thereto in Section 2(c) hereof.

“ Trust Indenture Act ” means the Trust Indenture Act of 1939, or any successor thereto, and the rules, regulations and forms promulgated thereunder, as the same shall be amended from time to time.

The term “ underwriter ” means any underwriter, or any person deemed to be an underwriter pursuant to the Securities Act and Exchange Act and the respective rules and regulations thereunder, as in effect at any relevant time, of Registrable Securities in connection with an offering thereof under a Shelf Registration Statement.

Wherever there is a reference in this Agreement to a percentage of the “principal amount” of Registrable Securities or to a percentage of Registrable Securities, each share of Common Stock issued upon conversion of the Securities shall represent a principal amount or percentage of Registrable Securities determined based on a quotient, (i) the numerator of which shall be equal to the aggregate principal amount of Securities issued, less the aggregate principal amount of Securities outstanding as of the date of determination, and (ii) the denominator of which shall be equal to the aggregate number of shares of Common Stock issued upon conversion of the Securities as of the date of determination.

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(a) The Company shall, no later than 90 calendar days following the Issue Date, file with the Commission a Shelf Registration Statement relating to the offer and sale of the Registrable Securities by the Holders from time to time in accordance with the methods of distribution elected by such Holders and, thereafter, shall use its reasonable best efforts to cause such initial Shelf Registration Statement to be declared effective under the Securities Act no later than 180 calendar days following the Issue Date; provided, however, that no Holder shall be entitled to be named as a selling securityholder in any Shelf Registration Statement as of the date it is declared effective or to use the Prospectus forming a part thereof for offers and resales of Registrable Securities unless such Holder is a Notice Holder.

(b) The Company shall use its reasonable best efforts:

(i) to keep any Shelf Registration Statement effective, supplemented and amended as required by the provisions of Section 3(j) hereof, in order to permit the Prospectus forming a part thereof to be usable by Holders until the earliest of: (1) two years after the last date of original issuance of any Securities; (2) the Holders of Registrable Securities that are not Affiliates of the Company are able to sell all Registrable Securities immediately in accordance with the provisions of Rule 144(k) under the Securities Act or any successor rule thereto; (3) all Registrable Securities are registered under the Shelf Registration Statement have been disposed of in accordance with the Shelf Registration Statement or (4) all Registrable Securities have ceased to be outstanding (whether as a result of repurchase and cancellation, conversion or otherwise) or been disposed of in accordance with the Shelf Registration Statement (such period being referred to herein as the “Effectiveness Period”); and

(ii) after the Effective Time of the initial Shelf Registration Statement to take the actions provided for in Section 3(a)(ii) hereof after the receipt of a completed and signed Notice and Questionnaire from any Holder of Registrable Securities that is not then a Notice Holder.

The Company shall be deemed not to have used its reasonable best efforts to keep any Shelf Registration Statement effective during the Effectiveness Period if the Company voluntarily takes any action that would result in Holders of Registrable Securities covered thereby not being able to offer and sell any of such Registrable Securities under such Shelf Registration Statement during that period, unless such action is (A) required by applicable law and the Company thereafter promptly complies with the requirements of Section 3(j) hereof or (B) permitted pursuant to Section 2(c) hereof.

(c) The Company may suspend the use of any Prospectus for a period not to exceed 45 calendar days in any 90 calendar day period or an aggregate of 120 calendar days in any 360 calendar day period, (each, a “Suspension Period”) if the Board of Directors of the Company shall have determined in good faith that because of valid business reasons (not including avoidance of the Company’s obligations hereunder), including the acquisition or divestiture of assets, pending corporate developments and similar events or because of filings with the Commission, it is in the best interests of the Company to suspend such use, and prior to suspending such use the Company provides the Holders with written notice of such suspension, which notice need not specify the nature of the event giving rise to such suspension; provided,

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that in the event the disclosure relates to a previously undisclosed proposed or pending material business transaction, the disclosure of which would impede the Company’s ability to consummate such transaction, the Company may extend a Suspension Period from 45 calendar days to 60 calendar days; provided, however, that Suspension Periods (including, without limitation, any such extension of a Suspension Period) shall not exceed an aggregate of 120 calendar days in any 360 calendar day period. Each Holder shall keep confidential any communications received by it from the Company regarding the suspension of the use of the Prospectus, except as required by applicable law.

In connection with the Shelf Registration Statements, the following provisions shall apply:

(a) (i) Not less than 30 calendar days prior to the time the Company in good faith intends to have the initial Shelf Registration Statement declared effective, the Company shall distribute the Notice and Questionnaire to the Holders of Registrable Securities. The Company shall take action to name as a selling securityholder in the initial Shelf Registration Statement at the Effective Time each Holder that completes, executes and delivers a Notice and Questionnaire to the Company at the address set forth in the Notice and Questionnaire (a “Notice Holder”) prior to or on the 20th calendar day after such Holder’s receipt thereof so that such Holder is permitted to deliver the Prospectus forming a part thereof as of such time to purchasers of such Holder’s Registrable Securities in accordance with applicable law. The Company shall not be required to take any action to name any Holder as a selling securityholder in the initial Shelf Registration Statement at the time of its effectiveness or to enable any Holder to use the Prospectus forming a part thereof for resales of Registrable Securities unless such Holder has returned a completed and signed Notice and Questionnaire to the Company in a timely manner.

(ii) After the Effective Time of the initial Shelf Registration Statement, the Company shall, upon the request of any Holder of Registrable Securities that is not then a Notice Holder, promptly send a Notice and Questionnaire to such Holder. From and after the Effective Time of the initial Shelf Registration Statement, the Company shall (A) after the date a completed and signed Notice and Questionnaire is delivered to the Company, prepare and file with the Commission (x) a supplement to the Prospectus as soon as practicable or, if required by applicable law, a post-effective amendment to the Shelf Registration Statement or an additional Shelf Registration Statement as soon as reasonably practicable after the end of each fiscal quarter and (y) any other document required by applicable law, so that the Holder delivering such Notice and Questionnaire is named as a selling securityholder in a Shelf Registration Statement and is permitted to deliver the Prospectus to purchasers of such Holder’s Registrable Securities in accordance with applicable law, and (B) if the Company shall file a post-effective amendment to the Shelf Registration Statement, or an additional Shelf Registration Statement, use its reasonable best efforts to cause such post-effective amendment or such additional Shelf Registration Statement to become effective under the Securities Act as soon as practicable; provided, however, that if a Notice and Questionnaire is delivered to

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the Company during a Suspension Period, the Company shall not be obligated to take the actions set forth in this clause (ii) until the termination of such Suspension Period.

(b) The Company shall furnish to each Notice Holder who so requests, prior to the Effective Time, a copy of the Shelf Registration Statement initially filed with the Commission, and shall furnish to such Notice Holders, prior to the filing with the Commission, copies of each substantive amendment thereto and each amendment or supplement, if any, to the Prospectus included therein (other than supplements solely for the purpose of naming one or more Notice Holders as selling securityholders), and shall use its best efforts to reflect in each such document, at the Effective Time or when so filed with the Commission, as the case may be, such comments as such Notice Holders and their respective counsel reasonably may propose.

(c) The Company shall promptly take such action as may be necessary so that (i) each of the Shelf Registration Statements and any amendment thereto and the Prospectus forming a part thereof and any amendment or supplement thereto (and each report or other document incorporated therein by reference in each case) complies in all material respects with the Securities Act and the Exchange Act and the respective rules and regulations thereunder, as in effect at any relevant time, (ii) each of the Shelf Registration Statements and any amendment thereto does not, when it becomes effective, contain an 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 not misleading, and (iii) each Prospectus forming a part of any Shelf Registration Statement, and any amendment or supplement to such Prospectus, in the form delivered to purchasers of the Registrable Securities during the Effectiveness Period, does not include an 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 under which they were made, not misleading.

(d) The Company shall promptly advise each Notice Holder, and shall confirm such advice in writing if so requested by any such Notice Holder:

(i) when the initial Shelf Registration Statement has been filed with the Commission and when the initial Shelf Registration Statement has become effective;

(ii) when any supplement to the Prospectus, Shelf Registration Statement or post-effective amendment to a Shelf Registration has been filed with the Commission and, with respect to a Shelf Registration Statement or any post-effective amendment, when the same has been declared effective by the Commission;

(iii) of any request by the Commission for amendments or supplements to any Shelf Registration Statement or the Prospectus included therein or for additional information;

(iv) of the issuance by the Commission of any stop order suspending the effectiveness of any Shelf Registration Statement or the initiation of any proceedings for such purpose;

(v) of the receipt by the Company of any notification with respect to the suspension of the qualification of the securities included in any Shelf Registration Statement for sale in any jurisdiction or the initiation of any proceeding for such purpose; and

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(vi) of the happening of any event or the existence of any state of facts that requires the making of any changes in any Shelf Registration Statement or the Prospectus included therein so that, as of such date, such Shelf Registration Statement and Prospectus do not contain an untrue statement of a material fact and do not omit to state a material fact required to be stated therein or necessary to make the statements therein (in the case of the Prospectus, in the light of the circumstances under which they were made) not misleading (which advice shall be accompanied by an instruction to such Holders to suspend the use of the Prospectus until the requisite changes have been made, which notice need not specify the nature of the event giving rise to such suspension).

(e) The Company shall use its best efforts to prevent the issuance, and if issued to obtain the withdrawal at the earliest possible time, of any order suspending the effectiveness of any Shelf Registration Statement.

(f) As promptly as reasonably practicable furnish to each Notice Holder and the Initial Purchaser, upon their request and without charge, at least one (1) conformed copy of the Registration Statement and any amendment thereto, but excluding schedules, all documents incorporated or deemed to be incorporated therein by reference and all exhibits (unless requested in writing to the Company by such Notice Holder or Initial Purchaser, as the case may be).

(g) The Company shall, during the Effectiveness Period, deliver to each Notice Holder, without charge, as many copies of each Prospectus in which the Notice Holder is listed as a selling securityholder included in the applicable Shelf Registration Statement and any amendment or supplement thereto as such Notice Holder may reasonably request; and the Company consents (except during a Suspension Period or during the continuance of any event described in Section 3(d) (iii)-(vi) above) to the use of the Prospectus and any amendment or supplement thereto by each of the Notice Holders in connection with the offering and sale of the Registrable Securities covered by the Prospectus and any amendment or supplement thereto during the Effectiveness Period.

(h) Prior to any offering of Registrable Securities pursuant to a Shelf Registration Statement, the Company shall (i) register or qualify or cooperate with the Notice Holders and their respective counsel in connection with the registration or qualification (or exemption from such registration or qualification) of such Registrable Securities for offer and sale under the securities or “blue sky” laws of such jurisdictions within the United States as any Notice Holder may reasonably request, (ii) keep such registrations or qualifications or exemption therefrom in effect and comply with such laws so as to permit the continuance of offers and sales in such jurisdictions for so long as may be necessary to enable any Notice Holder or underwriter, if any, to complete its distribution of Registrable Securities pursuant to such Shelf Registration Statement, and (iii) take any and all other actions necessary or advisable to enable the disposition in such jurisdictions of such Registrable Securities; provided, however , that in no event shall the Company be obligated to (A) qualify as a foreign corporation or as a dealer in securities in any jurisdiction where it would not otherwise be required to so qualify but for this Section 3(h) or (B) subject itself to general or unlimited service of process or to taxation in any such jurisdiction if they are not now so subject.

(i) Unless any Registrable Securities shall be in book-entry only form, the Company shall cooperate with the Notice Holders to facilitate the timely preparation and delivery of certificates representing Registrable Securities to be sold pursuant to any Shelf Registration

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Statement, which certificates, if so required by any securities market or exchange upon which any Registrable Securities are quoted or listed, shall be penned, lithographed or engraved, or produced by any combination of such methods, on steel engraved borders, and which certificates shall be free of any restrictive legends and in such permitted denominations and registered in such names as Notice Holders may request in connection with the sale of Registrable Securities pursuant to such Shelf Registration Statement.

(j) Upon the occurrence of any fact or event contemplated by paragraph 3(d)(vi) above, subject to Section 2(c) hereof, the Company shall promptly, but in any event within 5 Business Days following such occurrence, prepare, file (and have declared effective) a post-effective amendment to any Shelf Registration Statement or an amendment or supplement to the related Prospectus included therein or file any other document with the Commission so that, as thereafter delivered to purchasers of the Registrable Securities, the Prospectus will not include an untrue statement of a material fact or omit to state any material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading. If the Company notifies the Notice Holders of the occurrence of any fact or event contemplated by paragraph 3(d)(vi) above, the Notice Holder shall suspend the use of the Prospectus until the requisite changes to the Prospectus have been made.

(k) Not later than the Effective Time of a Shelf Registration Statement, the Company shall provide a CUSIP number for the debt securities to be sold pursuant to a Shelf Registration Statement.

(l) The Company shall comply with the Securities Act and the Exchange Act and the respective rules and regulations thereunder, as in effect at any relevant time, and make generally available to its securityholders earnings statements (which need not be audited) satisfying the provisions of Section 11(a) of the Securities Act and Rule 158 thereunder (or any similar rule promulgated under the Securities Act) no later than 45 days after the end of any 12-month period (or 90 days after the end of any 12-month period if such period is a fiscal year), or such shorter period as required by the Securities Act and the Exchange Act and the rules and regulations thereunder, as in effect at any relevant time, commencing on the first day of the first fiscal quarter of the Company commencing after (i) the effective date of a Shelf Registration Statement, (ii) the effective date of each post-effective amendment to such Shelf Registration Statement, or (iii) the date of each filing by the Company with the Commission of an Annual Report on Form 10-K that is incorporated by reference in such Shelf Registration Statement, which statements shall cover said 12-month periods.

(m) Not later than the Effective Time of the initial Shelf Registration Statement, the Company shall cause the Indenture to be qualified under the Trust Indenture Act; in connection with such qualification, the Company shall cooperate with the Trustee under the Indenture and the Holders (as defined in the Indenture) to effect such changes to the Indenture as may be required for such Indenture to be so qualified in accordance with the terms of the Trust Indenture Act; and the Company shall execute, and shall use all reasonable efforts to cause the Trustee to execute, all documents that may be required to effect such changes and all other forms and documents required to be filed with the Commission to enable such Indenture to be so qualified in a timely manner. In the event that any such amendment or modification referred to in this Section 3(m) involves the appointment of a new trustee under the Indenture, the Company shall appoint a new trustee thereunder pursuant to the applicable provisions of the Indenture.

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(n) The Company shall enter into such customary agreements and take all such other necessary actions in connection therewith (including those reasonably requested by the holders of a majority of the Registrable Securities being sold) in order to expedite or facilitate disposition of such Registrable Securities; provided, that the Company shall not be required to take any action in connection with an underwritten offering without its consent.

(o) The Company shall make reasonably available for inspection by one or more representatives of the selling Holders, designated in writing by a Majority of Holders whose Registrable Securities are included in a Shelf Registration Statement, any underwriter participating in any disposition pursuant to any Shelf Registration Statement, and any attorney, accountant or other agent retained by such Notice Holders or any su