WASHINGTON - The Treasury Department plans to announce as early Wednesday afternoon that it will give GMAC Inc. around $3.5 billion in additional capital, sources told The Detroit News.

Detroit-based GMAC and the Treasury Department have been in talks for months to finalize the amount of money the company would receive. The Treasury Department said earlier this year it would invest up to $5.6 billion more in GMAC -- on top of $13.4 billion GMAC has received over the last year.

GMAC spokeswoman Gina Proia declined to say how much the company expected to get.

"As we have previously stated, GMAC has been conducting a strategic review of its business and evaluating options to address the challenges at ResCap and the mortgage operations," Proia said referring to GMAC's residential mortgage unit. "Critical objectives in the process would be to take actions that position GMAC for improved financial performance and to repay the U.S. government."

GMAC obtained bank holding status last December making it eligible for Treasury aid. However, unlike other financial institutions that went through "stress tests," the Detroit-based auto finance company wasn't able to raise enough outside capital to assure regulators that it was prepared for a new downturn.

The Treasury Department holds a 35.4 percent equity stake in the company. An official announcement on new funding is expected in the coming days, officials said.

GMAC is the primary lender to most GM and Chrysler dealers and customers, and its financial health is critical to the domestic auto industry's turnaround.