The Federal Reserve will pump an additional $630 billion into the global financial system, flooding banks with cash to alleviate the worst banking crisis since the Great Depression.

The Fed increased its existing currency swaps with foreign central banks by $330 billion to $620 billion to make more dollars available worldwide. The Term Auction Facility, the Fed's emergency loan program, will expand by $300 billion to $450 billion.

The Fed's expansion of liquidity, the biggest since credit markets seized up last year, comes as Congress prepares to vote on a $700 billion bailout for the financial industry.