GMAC LLC said Thursday it would not inherit Chrysler Financial's book of existing auto loans and leases, even as GMAC assumes the mantle of lender for new financing to Chrysler LLC dealers and consumers.

This could be a win-win for GMAC, the former lending arm of General Motors Corp. (GM). GMAC turned itself into a bank in December in an effort to garner federal funds required for the strapped lender's survival. The pact with Chrysler means that GMAC won't be saddled with problems that could arise in Chrysler Financial's existing portfolio, stemming from Chrysler's trip to bankruptcy court.

At the same time, being the new lending arm to Chrysler dealers and consumers helps GMAC satisfy its requirement as a bank-holding company to diversify its lending business away from GM.

"This certainly helps us to diversify our auto finance business," said Gina Proia, a GMAC spokeswoman.

"What's even more encouraging is that it's a business where we can continue to leverage our core competency," Proia said. "We have the resources and the capability in this sector."

Earlier Thursday, President Barack Obama said Chrysler will file for Chapter 11 bankruptcy protection the same day, kicking off what the administration predicts will be a 30- to 60-day restructuring of the third-largest U.S. auto maker.

In addition, the government would provide additional funding support to GMAC to ensure continued financing to Chrysler dealers and consumers while the auto maker restructured in bankruptcy court. The size of the additional federal funds isn't yet known. After its bank registration, GMAC got $5 billion under the U.S. Treasury's Troubled Asset Relief Program.

GMAC is jointly owned by GM and an investor group led by private-equity firm Cerberus Capital Management LP. The auto maker and the investor group will significantly scale back their ownership in GMAC as a condition of the lender becoming a bank-holding company. Aside from owning a substantial stake in GMAC and Chrysler, Cerberus owns all of Chrysler Financial. Chrysler used to control its finance arm but the two were turned into separate companies after Cerberus acquired Chrysler in 2007.

-By Aparajita Saha-Bubna, Dow Jones Newswires; 617-654-6729; aparajita.saha-bubna@dowjones.com