WASHINGTON – General Motors has reached a deal with a private investment group to sell a majority stake in its GMAC financing unit, reported the Washington Post.

The investor group is led by Cerberus Capital Management and includes Citigroup and Aozora Bank. The sale will give GM $14 billion during the next three years.

GM is selling the subsidiary so that GMAC's credit rating will no longer be tied to GM, which is at junk status. Better ratings would bring lower financing costs and greater earnings in the long term, GM has said.

In a statement, GM Chief Executive Rick Wagoner said the GMAC deal "provides significant liquidity to support our North American turnaround plan, finance future GM growth initiatives, strengthen our balance sheet and fund other corporate priorities."

GMAC’s earnings totaled just under $2.8 billion last year. Of the total, about $1 billion was generated by auto financing. GMAC's mortgage units brought in $1.4 billion, and its insurance business $417 million.

As part of the deal, the automaker said GM and GMAC will enter into a number of 10-year agreements under which GMAC will continue to support GM's automotive operations, GM said.

Cerberus, based in New York, has $18 billion in assets under management for individual and institutional investors, including state and corporate pension funds, insurance companies, foundations and endowments, according to the Washington Post.