This excerpt taken from the SIRI 8-K filed Nov 12, 2009.
Section 11. Amendment or Termination
(a) This Trust Agreement may be amended by a written instrument executed by Trustee and Company. Notwithstanding the foregoing, no such amendment shall conflict with the terms of the Agreement or shall make the Trust revocable after it has become irrevocable in accordance with Section l(b) hereof.
(b) The Trust shall not terminate until the date on which Executive and his beneficiaries are no longer entitled to benefits pursuant to the terms of the Agreement, at which time the Trust shall terminate. Company shall provide Trustee with notice that Executive and his beneficiaries are no longer entitled to benefits pursuant to the terms of the Agreement, and Trustee shall be entitled to rely on such notice. Upon termination of the Trust any assets remaining in the Trust shall be returned to Company.