(Recasts, adds details on potential impact on GM sales volume, updates shares)

By Jonathan Stempel

NEW YORK, Jan 2 (Reuters) - GMAC LLC on Friday said that as part of its $6 billion federal bailout and decision to become a bank, it will no longer have the exclusive right to provide low-interest loans to borrowers who buy General Motors Corp (GM.N: Quote, Profile, Research) cars and trucks.

According to a U.S. Securities and Exchange Commission filing, GM may now offer incentives such as low-interest loans through other lenders, subject to restrictions. Some of these restrictions will be lifted in December 2010, and the rest in December 2013, the filing said.

The change may help GM sell more vehicles, and rely less on GMAC's ability to provide credit. GM sales fell 41 percent in November after GMAC had significantly tightened credit the prior month, leaving many prospective buyers unable to borrow. GMAC eased its lending requirements after getting the bailout.

Also in the filing, GMAC said it will have no obligation to finance vehicle leases. GMAC has lost money on leases because trade-in values are falling, especially on less fuel-efficient models such as large sport-utility vehicles.

GMAC is the main lender to GM customers, and also finances dealer inventories. It had previously paid GM an annual exclusivity fee and was required to meet various financing targets for loans and leases under an agreement that had been in effect through November 2016, the SEC filing said.

Both companies are based in Detroit.

On Dec. 29 the U.S. Treasury Department gave GMAC $5 billion from its $700 billion Troubled Asset Relief Program, and agreed to lend GM up to $1 billion to support GMAC. Five days earlier, the Federal Reserve granted GMAC bank holding company status, allowing it to tap lower-cost funding.