An Obama administration official said the government will put in $75 billion to $100 billion from its bailout fund to partner with private investors and buy troubled assets from banks, a long-awaited bid to target the heart of the credit crisis.

It remains to be seen whether hedge funds and other investors will join the plan. Many are concerned at the anger that has been leveled at Wall Street by lawmakers who are seeking to claw back bonuses from companies rescued with public funds.

The program seeks to put government money alongside private capital and leverage that to $500 billion, or possibly double that amount, with the help of the Federal Deposit Insurance Corp, a US bank regulator, and the Federal Reserve.

When Treasury Secretary Timothy Geithner first sketched out his idea for public-private partnerships in February, a lack of detail sent markets tumbling out of fear Washington was moving too slowly to contain the credit crisis.

Now, the plan's success is seen as a critical test for Geithner, who has been in office for less than two months. He will brief the media at 8:45 a.m. (1245 GMT).

Under the program he has crafted, the government will provide the lion's share of the funding to buy up soured assets.