FOREX-Dollar falls as credit woes cut Fed rate hike chances

* Dollar falls as credit fears further darken market mood

* Euro rises to 2-1/2-month high vs dollar

* U.S. lawmaker raises hopes on discount window option (Recasts, updates prices, changes byline)

The dollar fell broadly on Friday as persistent worries about the stability of two U.S. mortgage finance giants were seen constraining the Federal Reserve's ability to raise interest rates this year.

The greenback briefly got some support versus the yen, however, after a source told Reuters Fed Chairman Ben Bernanke had said embattled mortgage finance houses Freddie Mac (FRE.N: Quote, Profile, Research) and Fannie Mae (FNM.N: Quote, Profile, Research) would qualify for discount window borrowing.

But a Fed spokeswoman later said the U.S. central bank had had no discussions with the two government-sponsored firms about access to that emergency lending facility.

Separately, a senior U.S. lawmaker said the Fed and the Treasury Department were considering opening the discount window.

"Ongoing concerns about the fragility of Fannie Mae and Freddie Mac have again underscored the likely inability of the Federal Reserve to raise rates any time soon," said Shankar Samarjit, global FX strategist at Bank of New York Mellon in Boston.