Rule 2012. Substitution of Trustee or Successor Trustee; Accounting
(a) Trustee. If a trustee is appointed in a chapter 11 case or the debtor is removed as debtor in possession in a chapter 12 case, the trustee is substituted automatically for the debtor in possession as a party in any pending action, proceeding, or matter.
(b) Successor Trustee. When a trustee dies, resigns, is removed, or otherwise ceases to hold office during the pendency of a case under the Code
(1) the successor is automatically substituted as a party in any pending action, proceeding, or matter; and
(2) the successor trustee shall prepare, file, and transmit to the United States trustee an accounting of the prior administration of the estate.