Exhibit 10.8

THIS CONSENT AND AMENDMENT AGREEMENT IS NOT AN OFFER TO ISSUE OR SELL, OR A
SOLICITATION OF AN OFFER TO ACQUIRE OR BUY, SECURITIES. SUCH OFFER OR
SOLICITATION ONLY WILL BE MADE IN COMPLIANCE WITH ALL APPLICABLE SECURITIES
LAWS.

CONSENT AND AMENDMENT AGREEMENT

CONSENT AND AMENDMENT AGREEMENT (this “Consent”), dated as of July 10, 2008, by
and among XM Satellite Radio Holdings Inc. (the “Issuer”) and the undersigned
institutions, severally, but not jointly and severally (each such institution, a
“Holder” and collectively, all such institutions, the “Holders”). For purposes
hereof, all references in this Consent to Holders shall mean, as of any date of
determination, those Holders or parties, as the case may be, that on or before
such date of determination executed and delivered a counterpart signature page
to this Consent substantially in the form attached as Exhibit A hereto, together
with any transferee of Bonds (as hereinafter defined) beneficially owned by such
Holders that have executed and delivered a joinder signature page to this
Consent.

W I T N E S S E T H:

Reference is made to the agreement (the “Agreement”), dated as of June 26, 2008,
by and among XM Satellite Radio Holdings Inc. (the “Issuer”), the Holders (as
defined in the Agreement), solely for purposes of Section 21 of the Agreement,
Brown Rudnick LLP (“Brown Rudnick”), and solely for purposes of Section 22,
Sirius Satellite Radio Inc. (“Sirius”). All capitalized terms used and not
otherwise defined in this Consent shall have the meanings ascribed thereto in
the Agreement.

WHEREAS, each of the Holders is the beneficial owner of, or the investment
adviser or manager for the beneficial owners of (with the power and authority to
vote and dispose of), the Bonds in the aggregate principal amount set forth
opposite its name on Exhibit A (the “Consent Participating Bonds”);

WHEREAS, the Consent Participating Bonds represent between 98.8% and 100% of the
principal amount of the Bonds,

WHEREAS, the Issuer has determined that commencement and consummation of the
Offer contemplated by Section 2 of the Agreement is undesirable and has
proposed, in lieu of the Offer, to amend the Bond Indenture to effect the New
Rate for all Holders and other holders of Bonds as an Alternative Transaction
within the meaning of Section 8 of the Agreement;

WHEREAS, Section 10 of the Agreement provides that a consent by Holders of not
less than a majority of the aggregate principal amount of the Participating
Bonds shall constitute the consent of all Holders;

WHEREAS, subject to the terms and conditions hereof, each of the undersigned
Holders (the “Consenting Holders”) has agreed, among other things, to consent to
the Alternative Transaction;

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NOW, THEREFORE, in consideration of the premises and the mutual covenants and
agreements set forth herein, and for other good and valuable consideration, the
receipt and sufficiency of which are hereby acknowledged, the Issuer and the
Consenting Holders hereby agree as follows:

1. Effectiveness of this Consent. The effectiveness of this Consent, and the
respective obligations of the parties hereto, are conditioned upon the execution
of this Consent by the Issuer and Consenting Holders who, in the aggregate,
beneficially own, or are the investment advisors or managers for the beneficial
owners of (with the power and authority to vote and dispose of), (i) more than
fifty percent (50%) of the Consent Participating Bonds and (ii) more than fifty
percent (50%) of the outstanding principal amount of the Bonds.

2. Indenture Amendment: The Issuer shall take all action reasonably necessary to
amend the Bond Indenture (and the definitive global securities representing the
Bonds) (the “Indenture Amendment”) to (x) increase the interest rate applicable
to the Bonds to 10% (the “New Rate”) and (y) indicate that the Merger does not
constitute a Fundamental Change (as defined in Article I of the Bond Indenture)
for purposes of Article V of the Bond Indenture and to waive any notice with
respect thereto, with respect to the Consent Participating Bonds (which Consent
Participating Bonds may not be accelerated on any basis that the Merger
constitutes a Fundamental Change (as defined in Article I of the Bond
Indenture)), including, without limitation, furnishing the Bond Indenture
trustee with such instructions, documents, opinions and certificates as may be
required by such trustee pursuant to and in accordance with the Bond Indenture.
The Indenture Amendment shall be effective by no later than three (3) business
days following the consummation of the Merger (the “Latest Indenture Amendment
Date”); provided, that the provisions of the Indenture Amendment that establish
the New Rate shall not become effective prior to the consummation of the Merger.
The New Rate shall commence to accrue retroactively to July 2, 2008. The
Indenture Amendment shall constitute an Alternative Transaction for all purposes
of the Agreement and all undertakings and obligations of the Issuer to make the
Offer pursuant to Section 2(b) of the Agreement (and obligations and
undertakings ancillary thereto) shall be terminated, provided, however, that if
the Indenture Amendment has not become effective on or before the Latest
Indenture Amendment Date for any reason, this Consent shall be of no further
force and effect and all provisions of the Agreement, including the provisions
of Section 2(b) thereof, shall be reinstated, provided, further, that the date
set forth in Section 6(b)(ii) of the Agreement shall be extended to the date
which is ten (10) business days following the Latest Indenture Amendment Date.

3. Non-Participating Bonds. The parties hereto agree that (i) the Indenture
Amendment described in clause (y) of Section 2 above shall have no force and
effect as to the remaining Bonds, if any, beneficially owned by Holders to whom
notice of the Offer or the Amendment has been provided (which notice may be in
the form of a press release) but who have not executed this Consent (or a
joinder to this Consent) and therefore do not constitute Consent Participating
Bonds (the “Non-Participating Bonds”) and (ii) the Indenture Amendment described
in clause (x) of Section 2 above shall be effective as to the Non-Participating
Bonds to the same extent (and subject to the same conditions) as such Indenture
Amendment shall be effective as to Consent Participating Bonds.

 

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4. Definitive Documentation. No later than July 17, 2008, the Issuer shall
provide the Initial Holders with a draft of the Indenture Amendment. The
Indenture Amendment shall be subject to the reasonable review and comment of the
Initial Holders and shall be subject to approval of the Bond Indenture trustee.

5. Authority. Each of the Consenting Holders represents that, as of the date of
this Consent, it is the beneficial owner of, or the authorized investment
adviser or manager for the beneficial owners of, the principal amount of the
Bonds identified on Exhibit A annexed to its counterpart or joinder signature
page, with the power and authority to vote and dispose of the Bonds described
therein. Each Holder shall deliver its respective Exhibit A to Brown Rudnick,
and neither such Exhibit A nor the information contained therein shall be
provided to any other Holder. Brown Rudnick shall deliver copies of each Exhibit
A to the Issuer, which shall keep the contents thereof confidential; provided,
that the Issuer may disclose such copies of each Exhibit A to the Bond Indenture
trustee if such trustee agrees in writing to keep the contents thereof
confidential.

6. Press Release. Promptly, but in any event within one (1) business day of the
effectiveness of this Consent, the Issuer will issue a press release announcing
its intention to effect the Indenture Amendment in lieu of the Offer. Promptly,
but in any event within one (1) business day of the effective date of the
Indenture Amendment, the Issuer will issue a press release announcing the
effectiveness of the Indenture Amendment and that the Holders no longer need to
comply with the joinder requirement of Section 9 hereof. The Issuer shall
forward a copy of each such press release to Brown Rudnick.

7. Survival of Other Terms and Provisions of the Agreement. Except with respect
to matters expressly set forth in this Consent, all terms and provisions of the
Agreement, including, without limitation, the Waiver, the undertaking provisions
of Section 3 of the Agreement, the Holders’ Consent, the provisions of Section 6
(except for Section 6(b)(ii), which is expressly amended above) and Section 17
and shall remain in full force and effect.

8. Authority and Non-Contravention. Each of the parties hereto makes the same
representations and warranties with respect to this Consent as it made with
respect to the Agreement pursuant to Section 9(a) of the Agreement.

9. Transfers. From the date hereof until the earlier of the termination of the
Agreement or the effectiveness of the Indenture Amendment (the “Consent
Period”), no Holder shall sell, transfer or assign any of the Bonds or any
option thereon or any right or interest (voting or otherwise) therein, unless
(a) the transferee agrees in writing to be bound by all of the terms and
conditions of this Consent and the Agreement by executing a joinder to this
Consent in the form set forth on Exhibit B hereto; and (b) such transferee
provides a copy of such executed signature page to Brown Rudnick. Brown Rudnick
promptly shall deliver copies of each such Exhibit B to the Issuer, which shall
keep the contents thereof confidential; provided, that the Issuer may disclose
such copies of each Exhibit A to the Bond Indenture trustee if such trustee
agrees in writing to keep the contents thereof confidential.

 

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10. Trustee Instruction. Upon the Effective Date of this Agreement, the Holders
shall deliver an instruction to the Trustee in the form set forth on Exhibit C.

11. Amendments and Modifications. Except as otherwise expressly provided herein,
this Consent shall not be amended, modified or supplemented, except in writing
signed by all of the parties hereto, provided that a consent by Holders of not
less than a majority of the aggregate principal amount of the Consent
Participating Bonds shall constitute the consent of all parties hereto who are
Holders.

12. Governing Law. The Issuer and each Holder intend that their rights and
obligations under this Agreement shall be governed by the laws of the State of
New York, notwithstanding any conflicts of law provision or doctrine that would
apply the law of any other jurisdiction.

13. Successors and Assigns. This Agreement is intended to bind and inure to the
benefit of the parties hereto and their respective successors, permitted
assigns, heirs, executors, administrators and representatives. The agreements,
representations and obligations of the undersigned parties hereto are, in all
respects, several and not joint.

14. Severability. The invalidity or unenforceability of any provision of this
Consent shall not affect the validity or enforceability of any other provision
hereof.

15. Counterparts. This Consent may be executed in one or more counterparts, each
of which shall be deemed an original and all of which shall constitute one and
the same agreement. Delivery of an executed counterpart of a signature page by
telecopier shall be effective as delivery of a manually executed counterpart.

16. Third-Party Beneficiaries. The Trustee under the Bond Indenture shall be
deemed a third-party beneficiary of this Consent and the Agreement. Except as
provided in the foregoing sentence or as otherwise expressly stated herein, this
Consent and the Agreement shall be solely for the benefit of the parties hereto
and thereto, respectively, and no other person or entity shall be a third-party
beneficiary hereof.

17. Entire Agreement. The Agreement and this Consent constitute the entire
agreement between the parties, and all promises, representations,
understandings, warranties and agreements with reference to the subject matter
hereof and inducements to the making of this Consent relied upon by any party
hereto, have been expressed herein or in the documents incorporated herein by
reference. To the limited extent of the maters expressly set forth in the
Agreement and this Consent, the Agreement and this Consent shall be deemed to
supersede any prior agreements of the parties.

 

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IN WITNESS WHEREOF, each Holder executing a signature page hereto and the
Issuer, have caused this Agreement to be executed and delivered by its duly
authorized officers as of the date first written above.

 

Issuer: XM SATELLITE RADIO HOLDINGS INC. By:  

/s/ Joseph J. Euteneuer

Name:   Joseph J. Euteneuer Title:   Executive Vice President and Chief
Financial Officer

 

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Exhibit A

COUNTERPART SIGNATURE PAGE

CONSENT AND AMENDMENT AGREEMENT

Dated                  ,2008

Reference is made to that certain Consent (the “Consent”) dated July     , 2008
among XM Satellite Radio Holdings Inc. and certain holders of the notes issued
pursuant to the Bond Indenture. Terms not defined herein shall the meanings
ascribed to such terms in the Consent.

The undersigned hereby agrees, on a several but not a joint and several basis,
to be bound by all of the terms and conditions of the Consent as a Holder
thereto. Pursuant to the Consent the undersigned shall deliver this executed
Counterpart Signature Page and its respective Schedule 1 to Brown Rudnick LLP,
fax no. (617) 289-0521, attention: Robert L. Murray, Esq.

IN WITNESS WHEREOF, the undersigned has caused this Counterpart Signature Page
to be executed and delivered by its duly authorized officers as of the date
first written above.

 

Name of Holder:

By:

 

 

Name:

 

Title:

 

Address:

 

 

 

  Fax:  

 

   

 

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Schedule 1 To Counterpart Signature Page

Holdings Information

For Consent and Amendment Agreement

 

Name of Holder: By:  

 

Name:   Title:  

Bonds:

$                                          outstanding principal of Bonds

 

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Exhibit B

JOINDER SIGNATURE PAGE

AGREEMENT

Dated                  ,2008

Reference is made to that certain Consent (the “Consent”) dated [    ], 2008
among XM Satellite Radio Holdings Inc. and certain holders of the notes issued
pursuant to the Bond Indenture. Terms not defined herein shall the meanings
ascribed to such terms in the Consent.

The undersigned transferee hereby agrees, on a several but not a joint and
several basis, to be bound by all of the terms and conditions of the Consent and
the Agreement as a Holder thereto. Pursuant to the Consent, the undersigned
shall deliver this executed Counterpart Signature Page and its respective
Schedule 1 to Brown Rudnick LLP, fax no. (617) 289-0521, attention: Robert L.
Murray, Esq.

The instruction provided to the trustee in the form set forth on Exhibit C to
the Consent remains in effect.

IN WITNESS WHEREOF, the undersigned has caused this Counterpart Signature Page
to be executed and delivered by its duly authorized officers as of the date
first written above.

 

Name of Holder:

By:

 

 

Name:

 

Title:

 

Address:

 

 

 

 

  Fax:  

 

   

 

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Schedule 1 To Joinder Signature Page

Holdings Information

 

Name of Holder: By:  

 

Name:   Title:  

Bonds:

$                                          outstanding principal of Bonds

 

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Exhibit C

TRUSTEE INSTRUCTION

In accordance with Section 8.5 of the Bond Indenture, the undersigned Holder of
the aggregate principal amount of the Notes set forth below as of the date
hereof, either directly or through its undersigned authorized representative,
hereby direct the Trustee as follows:

1. The Trustee is authorized and directed to enter into an amendment to the Bond
Indenture increasing the interest rate of the Notes from 1.75% to 10%, and

2. The undersigned Holder (for itself and its respective successor and assign)
hereby approves the merger of XM Satellite Radio Holdings Inc. with Vernon
Merger Corporation, a wholly-owned subsidiary of Sirius Satellite Radio Inc.
(the “Merger”), and such Holder (i) waives the right to assert, and the right to
direct the Trustee to assert, that the Merger constitutes a Fundamental Change
under Article V of the Bond Indenture, (ii) agrees that such Holder’s Notes may
not be accelerated on any basis that the Merger constitutes a Fundamental Change
(as defined in Article I of the Bond Indenture, and (iii) waives the right to
receive any notice under Article V of the Bond Indenture in connection with the
Merger

This Trustee Instruction is coupled with an interest and is irrevocable by the
undersigned Holder.

 

Name of Holder: By:  

 

Name:   Title:  

Bonds:

$                                          outstanding principal of Bonds

 

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