The Bank of Japan said it injected 800 billion yen (7.6 billion dollars) into the financial system in the 13th straight day of attempts to keep cash flowing.
The House of Representatives approved the revised 700-billion-dollar Wall Street bailout, on its second try, bowing to intense pressure to help avert a global economic meltdown.
President George W. Bush signed the bill and Treasury Secretary Henry Paulson pledged to "move rapidly" to implement the plan to buy up assets distressed by the housing collapse, in the largest US government economic intervention since the 1930s Great Depression.
"We will move rapidly to implement the new authorities, but we will also move methodically," Paulson said.
Federal Reserve chairman Ben Bernanke said the country had taken "a critical step" in stabilizing markets and restoring credit flows.
"The legislation is a critical step toward stabilizing our financial markets and ensuring an uninterrupted flow of credit to households and businesses," h