MOTIENT CORP
EXHIBIT 10.35H WAIVER UNDER REV. CREDIT AGREEMENT
<DOCUMENT>
<TYPE>EX-10
<SEQUENCE>5
<FILENAME>exhibit1035h.txt
<DESCRIPTION>EXHIBIT 10.35H WAIVER UNDER REV. CREDIT AGREEMENT
<TEXT>

                                                                 Exhibit 10.35h

                                                                  EXECUTION COPY

                                  NOTE ISSUANCE
                                WAIVER UNDER THE
                           REVOLVING CREDIT AGREEMENT



     WAIVER dated as of April 2, 2001 under the Revolving Credit Agreement dated
as of March 31, 1998 (as heretofore  amended,  the "Revolving Credit Agreement")
among MOTIENT  HOLDINGS  INC.  (formerly  AMSC  ACQUISITION  COMPANY,  INC. (the
"Borrower"),   MOTIENT   CORPORATION   (formerly   AMERICAN   MOBILE   SATELLITE
CORPORATION)  (the "Parent  Guarantor"),  the BANKS party thereto (the "Banks"),
MORGAN  GUARANTY  TRUST  COMPANY  OF  NEW  YORK,  as  Documentation  Agent  (the
"Documentation  Agent"),  and TORONTO DOMINION (TEXAS),  INC., as Administrative
Agent.


                              W I T N E S S E T H :

     WHEREAS,  the Parent  Guarantor  proposes to borrow up to $50,000,000  from
Rare Medium Group,  Inc. and/or its affiliates,  substantially  on the terms and
conditions set forth in the attached summary,  and proposes to retain 75% of the
Net Cash Proceeds of such transaction; and

     WHEREAS,  the undersigned Banks and the Shareholder  Guarantors are willing
to consent to the foregoing, on the terms and conditions set forth below;

     NOW, THEREFORE, the undersigned parties hereto agree as follows:

     SECTION 1. Definitions;  References.  Unless otherwise specifically defined
herein, each term used herein which is defined in the Revolving Credit Agreement
has the meaning assigned to such term in the Revolving Credit Agreement.



<PAGE>




                                        2

     SECTION 2.  Waivers.  To the extent (and only to the extent)  necessary  to
permit the transaction  referred to in the first recital above,  the undersigned
Banks waive compliance with the provisions of Sections  2.09(c)(i),  5.15, 5.16,
and 5.23 of the Revolving  Credit  Agreement.  The Parent Guarantor and Borrower
agree that 100% (in lieu of any lesser percentage that might otherwise apply) of
the  first  $16,500,000  in Net Cash  Proceeds  received  from the  Restructured
Satellite  Business  Transactions (as defined in the Waiver dated as of December
1,  2000) and the first  Reduction  Event to occur in 2002  shall be  applied to
prepay  Loans under the Term Credit  Agreement or reduce  commitments  under the
Revolving Credit Agreement.

     SECTION 3.  Representations  of Borrower and Parent Guarantor.  Each of the
Borrower  and  the  Parent  Guarantor  represents  and  warrants  that  (i)  the
representations  and warranties  set forth in Article 4 of the Revolving  Credit
Agreement  shall be true on and as of the  Effective  Date  and (ii) no  Default
shall have occurred and be continuing on such date.

     SECTION 4. Governing Law. This Waiver shall be governed by and construed in
accordance with the laws of the State of New York.

     SECTION  5.  Counterparts.  This  Waiver  may be  signed  in any  number of
counterparts, each of which shall be an original, with the same effect as if the
signatures thereto and hereto were upon the same instrument.

     SECTION 6. Effectiveness. This Waiver shall become effective as of the date
hereof on the date (the  "Effective  Date") when the  Documentation  Agent shall
have  received  a  counterpart  hereof  from each of the  Borrower,  the  Parent
Guarantor,  Hughes, SingTel, Baron Capital and the Required Banks signed by such
party or a facsimile or other written  confirmation (in form satisfactory to the
Documentation Agent) that such party has signed a counterpart hereof.

     SECTION  7.  Shareholder  Guarantor  Consent.  The  Shareholder  Guarantors
consent to the foregoing.



<PAGE>




     IN WITNESS  WHEREOF,  the parties hereto have caused this Waiver to be duly
executed as of the date first above written.



                                       MOTIENT HOLDINGS INC. (formerly
                                       AMSC ACQUISITION COMPANY, INC.)


                                       By:/s/Randy Segal
                                          -----------------------------------
                                            Name: Randy Segal
                                            Title: Senior Vice President


                                       MOTIENT CORPORATION (formerly
                                       AMERICAN MOBILE SATELLITE CORPORATION)


                                       By:/s/Randy Segal
                                          -----------------------------------
                                            Name: Randy Segal
                                            Title: Senior Vice President


                                       TORONTO DOMINION (TEXAS), INC.


                                       By:/s/Jano Mott
                                          -----------------------------------
                                            Name: Jano Mott
                                            Title:   Vice President


                                       MORGAN GUARANTY TRUST COMPANY OF NEW YORK


                                       By:/s/Robert Bottamedi
                                          -----------------------------------
                                            Name: Robert Bottamedi
                                            Title:   Vice President


<PAGE>



                                        4

                                       BANK OF AMERICA, N.A.


                                       By:/s/Brad W. DeSpain
                                          -----------------------------------
                                            Name:  Brad W. DeSpain
                                            Title: Managing Director


<PAGE>






                                       BANCA COMMERCIALE ITALIANA
                                       LOS ANGELES FOREIGN BRANCH


                                       By:
                                          -----------------------------------
                                            Name:
                                            Title:


                                       By:
                                           ----------------------------------
                                            Name:
                                            Title:


                                       BANCA DI ROMA - SAN FRANCISCO


                                       By:
                                          -----------------------------------
                                            Name:
                                            Title:


                                       By:
                                          -----------------------------------
                                            Name:
                                            Title:


                                       THE CHASE MANHATTAN BANK


                                       By:/s/Tracey Navin Ewing
                                          -----------------------------------
                                            Name:  Tracey Navin Ewing
                                            Title: Vice President


                                       CITICORP USA, INC.


                                       By:
                                          -----------------------------------
                                            Name:
                                            Title:


<PAGE>




                                       DEUTSCHE BANK AG, NEW YORK BRANCH AND/OR
                                       CAYMAN ISLANDS BRANCH


                                       By:
                                          -----------------------------------
                                            Name:
                                            Title:


                                       By:
                                          -----------------------------------
                                            Name:
                                            Title:



                                       BANK ONE, N.A.


                                       By:
                                          -----------------------------------
                                            Name:
                                            Title:



                                       SANPAOLO IMI S.P.A.


                                       By:
                                          -----------------------------------
                                            Name:
                                            Title:


                                       By:
                                          -----------------------------------
                                            Name:
                                            Title:



<PAGE>




                                       HUGHES ELECTRONICS CORPORATION


                                       By:/s/M.J. Gaines
                                          -----------------------------------
                                            Name:  M.J. Gaines
                                            Title: Corp. V.P.


                                       SINGAPORE TELECOMMUNICATIONS LTD.


                                       By:/s/Tay Chek Khoon
                                          -----------------------------------
                                            Name:  Tay Chek Khoon
                                            Title: Vice Presidents



                                       BARON CAPITAL PARTNERS, L.P.,
                                        a Delaware limited partnership
                                       By: BARON CAPITAL MANAGEMENT, INC.,
                                        a general partner


                                       By:/s/Linda S. Martinson
                                          -----------------------------------
                                            Name:  Linda S. Martinson
                                            Title: V.P. & General Counsel




<PAGE>


               Summary of Secured Loan by Rare Medium ("Investor")
             of up to $50 million to Motient Corporation ("Company")
             -------------------------------------------------------


1.   The  Investor  will loan the  Company  up to $50  million.  At the  initial
     closing,  the  Investor  will loan the  Company $25 million and the Company
     will issue a promissory  note (the "Initial Note") to the Investor for such
     amount.  The initial  closing is expected to occur on April 2, 2001.  A two
     (2) point funding fee will be payable in cash at the time of each closing.

2.   The  Initial  Note will  carry  interest  at the rate of 12 1/2% per annum,
     which shall accrue and be payable at maturity.

3.   The Initial Note will mature,  and the principal and accrued interest shall
     be payable,  on the 180th day following the date of issuance of the Initial
     Note (the "Initial  Closing  Date").  The Initial Note  (including  accrued
     interest  thereon)  may be  prepaid  in  whole  or in part by the  Company,
     without penalty.

4.   At maturity,  the Company shall repay the  principal  and accrued  interest
     under the Initial Note (the "Repayment  Amount").  The Repayment Amount may
     be paid, at the Company's option, either in cash, or in unregistered shares
     of Class A common stock,  par value $.01 per share (the "XMSR Shares"),  of
     XM Satellite  Radio Holdings Inc., or in any  combination of the foregoing.
     If paid in XMSR Shares,  the number of XMSR Shares to be delivered shall be
     determined by dividing (A) the portion of the  Repayment  Amount to be paid
     in such  shares,  by (B) the  product of (i) the XMSR Share Price as of the
     maturity date and (ii) .95.

5.   To secure its  obligations  under the Initial Note, the Company will pledge
     to the  Investor  3,000,000  of its XMSR  Shares.  The Company may use such
     pledged XMSR Shares to satisfy its repayment or exchange  obligations under
     the Initial Note,  including,  without limitation,  its right to repay such
     note by delivering XMSR Shares as described above.

6.   In  accordance  with Section 7 of the Waiver dated as of April 2, 2001,  to
     which this summary is attached,  the Banks and Shareholder  Guarantors will
     retain a junior lien on any pledged XMSR Shares described above, until such
     time as the XMSR Shares are  delivered  to the Investor as payment of or in
     exchange for outstanding  principal and interest under the Initial Note. In
     addition,  the pledge  agreement  with  Investor  shall contain a provision
     requiring the Investor to release any XMSR Shares  remaining in the pledge,
     and return  them to the Banks'  collateral  agent,  after the  Company  has
     satisfied all its obligations under the Initial Note.

7.   An amount (the "Cash Collateral") equal to (A) the net cash proceeds of the
     Initial  Note,  less (B) the  amount  required  to be used to repay debt as
     described in the proposed waiver (i.e. $6.25 million), less (C) $4 million,
     shall be contributed into the Shareholder  Guarantors'  collateral pool, to
     secure the Company's  obligations to the Shareholder  Guarantors  under the
     Guaranty  Issuance  Agreement (as amended).  Any subsequent  release of the
     Cash  Collateral to the Company shall be subject to the written  consent of
     each of the three Shareholder Guarantors,  and shall be given in increments
     of no less than $1 million each.

8.   At the option of the  Company at any time after the Initial  Closing  Date,
     and assuming the accuracy of the  representations  and  warranties and that
     there is no  default at the time,  the  Investor  will loan the  Company an
     additional  amount (the "Second Loan"), in an amount equal to the lesser of
     (A) $25 million and (B) the difference  between (i) the product of the XMSR
     share price as of the closing date of the Second Loan (the "Second  Closing
     Date")  and  5,000,000,  and (ii) $25  million.  The  Company  will issue a
     promissory  note (the "Second  Note") to the Investor for the amount of the
     Second  Loan.  The Second  Note will carry the same  terms  (including  the
     maturity date) as the Initial Note.

9.   To secure its obligations under the Second Note, the Company will pledge to
     the Investor 2,000,000 of its XMSR Shares. The Company may use such pledged
     XMSR Shares to satisfy its  repayment  and exchange  obligations  under the
     Second Note, including, without limitation, its right to repay such note by
     delivering  XMSR  Shares as  described  above.  The pledge  agreement  will
     contain the same  provision  described  above,  requiring  the  Investor to
     release any XMSR  Shares  remaining  in the pledge,  and return them to the
     Banks'  collateral   agent,   after  the  Company  has  satisfied  all  its
     obligations under the Second Note.

10.  At any time, and from time to time, prior to maturity and prior to the date
     preceding the prepayment date set forth in a Company prepayment notice, the
     Investor  shall have the right to  exchange  the  Initial  Note  and/or the
     Second Note, or any portion  thereof,  for XMSR Shares.  The number of XMSR
     Shares  to be  delivered  upon any such  exchange  shall be  determined  by
     dividing (A) the  principal  amount of the Note to be exchanged (or portion
     thereof)  by (B) the  product of (i) the XMSR share  price as of either (a)
     the  Initial  Closing  Date  (in the case of the  Initial  Note) or (b) the
     Second Closing Date (in the case of the Second Note) and (ii) 1.5.

11.  If the  Company  makes an  offering  involving  its  equity  or  derivative
     securities  (of  the  Company  or  XMSR)  while  any  of the  Notes  remain
     outstanding,   the  Investor  shall  have  a  right  of  first  refusal  to
     participate in such offering.

12.  Subject to the provisos below,  the Banks and  Shareholder  Guarantors will
     release  up to 5  million  XMSR  shares  from the bank  collateral  pool (3
     million  shares for the  Initial  Loan and 2 million  shares for the Second
     Loan), as needed for delivery in connection with the Notes,  subject to the
     Banks and Shareholder  Guarantors  retaining a junior security  interest in
     such shares  until such time as the shares are  actually  delivered  to the
     Investor as payment of or in  exchange  for the Notes;  provided,  that any
     release of XMSR shares from the bank collateral pool in excess of 3 million
     shares  shall  be  subject  to the  written  consent  of each of the  three
     Shareholder Guarantors, provided further, that the 3 million shares for the
     Initial Loan will include the 1 million shares authorized for sale (but not
     yet  sold)  under the  Stock  Sale  Waiver  under  each of the Term  Credit
     Agreement  and  Revolving  Credit  Agreement  dated  October  18, 2000 (the
     "October 18, 2000 Waiver"). Notwithstanding the foregoing, in the event and
     when the Company seeks to sell the 1 million  shares  authorized  under the
     October 18, 2000 Waiver, 1 million  additional shares will be released from
     pledge upon request of the Company consistent with the terms of the October
     18, 2000 Waiver.

13.  The XMSR shares  described above may be disposed of in connection with this
     transaction  in the  following  ways:  (a)  delivered  to the  Investor  in
     satisfaction of a repayment  obligation or upon exchange of the Notes,  (b)
     pledged to the Investor as described  above,  or (c)  delivered to, or sold
     by,  the  Investor  in  connection  with the  Investor  foreclosing  on its
     security pursuant to the terms of the pledge described above.

14.  Upon delivery of any pledged Class B XMSR shares to Rare,  such shares will
     convert to Class A XMSR shares.


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