Mr Geithner extended the bail-out package to 3 October 2010
US Treasury Secretary Timothy Geithner has announced that the $700bn (£425bn) US financial bail-out fund will be extended until October next year.
The extension was "necessary to assist American families and stabilise financial markets", he said in a letter to congressional leaders.
But he pledged to deploy no more than $550bn of it.
The bail-out scheme was scheduled to expire at the end of the year but will now run until 3 October 2010.
The Troubled Asset Relief Program (Tarp) was established in the last few weeks of the Bush administration.
Money from the fund has helped rescue Wall Street banks, car makers and other companies.
On Tuesday, President Obama said in a speech that it was his intention to wind up the scheme.
Mr Geithner said that while many of the individual Tarp programmes would be wound down, "significant challenges remain".
"Too many American families, homeowners, and small businesses still face severe financial pressure. Although the economy is recovering, foreclosures are increasing, and unemployment is unacceptably high," he wrote.
He also confirmed that the long-term cost of Tarp would be $200bn less than the previous Treasury forecast of $341bn.
Meanwhile, government figures showed that US wholesale inventories unexpectedly rose in October for the first time in more than a year.
Wholesale inventories rose 0.3%, bringing an end to a record 13 consecutive months of declines, the Commerce Department said.