After promising last year to search its computers for tens of thousands of e-mails sent by White House officials, the Republican National Committee has informed a House committee that it no longer plans to retrieve the communications by restoring computer backup tapes, the panel's chairman said yesterday.

The move increases the likelihood that an untold number of RNC e-mails dealing with official White House business during the first term of the Bush administration -- including many sent or received by former presidential adviser Karl Rove -- will never be recovered, said House Democrats and public records advocates.