FOREX-Dollar rises as Bernanke calms financial markets

* Dollar rallies after Bernanke comments

* Bernanke says may keep Fed's emergency lending open

* U.S. pending home sales index drops in May (Updates prices, adds comments)

By Gertrude Chavez-Dreyfuss

NEW YORK, July 8 (Reuters) - The dollar rebounded broadly on Tuesday, lifted by comments from Federal Reserve Chairman Ben Bernanke, who said the central bank is willing to keep its emergency lending facility open beyond the end of the year for big Wall Street firms.

The Fed chief's remarks eased renewed credit worries after a Lehman Brothers report on Monday said a pending accounting change could force Fannie Mae (FNM.N: Quote, Profile, Research) and Freddie Mac (FRE.N: Quote, Profile, Research) to raise a combined $75 billion in capital.

Fannie and Freddie's regulator, the Office of Federal Housing Enterprise Oversight, also sought to appease those concerns, saying on Tuesday that a proposed accounting change should not spur capital changes at the two government-sponsored agencies.

"The FX market in general is heartened by Bernanke's extension of liquidity," said Win Thin, senior currency strategist, at bank Brown Brothers Harriman in New York.

"It shows that the Fed continues to remain flexible" in its efforts to unfreeze credit and instill calm in financial markets," he added.