W.House says will take weeks to start buying bad debt

WASHINGTON (Reuters) - The White House said on Thursday it was "fairly optimistic" the U.S. House of Representatives would pass a $700 billion (392 billion pounds) financial rescue bill on Friday, but it would likely take "at least weeks" for the Treasury Department to begin buying bad debt.

Passage of the bill would open the way for the rescue measure to be sent to President George W. Bush's desk to be signed into law.

"We feel fairly optimistic that we have a good chance for a successful vote tomorrow," White House spokesman Tony Fratto told reporters, adding that Bush had called about three dozen House members over the past two days to lobby them for their votes.

Asked how soon after the bill's passage Treasury would start buying up toxic debt clogging the financial system, he said: "Treasury wants to do it as quickly as possible but they can explain to you how they will implement this going forward.

"It's a complicated thing that they'll be trying to put in place. ... I think it's at least weeks," he said.

The Senate passed a revised $700 billion bailout plan on Wednesday night, and its fate now lies with the House, which had rejected an earlier version and is expected to vote on the new bill on Friday.

(Reporting by Matt Spetalnick; Editing by Leslie Adler)