The dropping of the presidential veto threat spurred investors to buy shares and bonds of mortgage finance companies Fannie Mae and Freddie Mac, which would receive an emergency government lifeline under the bill.
The House of Representatives was expected to approve the package later on Wednesday.
A White House spokeswoman said Bush will sign the measure because it is needed promptly to address the credit crisis. The White House has repeatedly expressed concern about a provision in the legislation that would provide grants to communities to buy and repair foreclosed homes.
"We do not believe we have time for a prolonged veto fight," spokeswoman Dana Perino said.