Several major banks and asset management companies have submitted proposals to participate in the Treasury Department's $700 billion financial rescue program.
Bids were due Wednesday evening.
BlackRock Inc. and Pacific Investment Management Co. bid to manage troubled mortgage-backed securities, the biggest portion of the bailout.
State Street Corp. and Bank of New York Mellon Corp. bid to handle record-keeping and custody services for the Treasury, according to people involved in the process.
Companies must oversee at least $100 billion of fixed-income assets for clients to compete for the contracts to buy and sell mortgage-backed securities under the plan, according to criteria released Oct. 6. Bidders to provide custody services must oversee at least $500 billion of investor assets.
The Treasury said it plans to make its selections by next week.
Treasury spokeswoman Jennifer Zuccarelli declined to comment. In a speech Wednesday, Treasury Secretary Henry Paulson said the department could begin to hire private firms this week.
Analysts with UBS AG said in a research report published Tuesday that the Treasury was "anxious" to begin buying mortgage assets but unsure about how the plan will work, suggesting purchases will begin in six to eight weeks.
The assets would likely be acquired through reverse auctions, in which the government would accept the lowest price offered by banks selling a type of asset. The Treasury expects the portfolio to hold assets until the markets improve, which it said may take months or years.
UBS said that "many details remain to be hammered out," including prices and which assets would be bought first. The buying will probably start with originally triple-A-rated securities backed by subprime or alternative-A home loans, in part because those prices have fallen the most.
The Treasury said in a notice posted on its Web site that it has asked the fixed-income asset managers to describe in detail their "expertise in the mortgage credit market and in managing distressed assets and mortgage-related assets."
"Given the lack of industry benchmarks or indices for a portfolio of distressed assets, and the Treasury's stated policy goals, describe the most effective metric for measuring your performance as an asset manager for the Treasury," the notice said.
The Treasury also plans to select firms to manage residential and commercial mortgages.
Officials have previously said the agency would like to hire five to 10 asset management firms, and about two dozen in-house employees.
BlackRock, Pacific Investment Management, and Legg Mason Inc., the three biggest U.S. fixed-income managers, informally advised the Treasury before passage of the rescue package.
The three firms collectively manage about $1.9 trillion of fixed-income assets.
Representatives of those three companies, as well as spokespeople for State Street and Bank of New York Mellon, would not say whether the companies had submitted bids.