GMAC Financial Services will offer General Motors Co and Chrysler Group LLC dealerships in the United States incentives to add to business with the former GM financing arm starting Oct. 1, a spokeswoman said on Friday.

GMAC has had rewards programs in the past and plans to run the new incentives indefinitely in the United States and to offer a similar program in Canada in the near future, spokeswoman Sue Mallino said.

GMAC, which is now held 35.4 percent by the U.S. Treasury after a government infusion of support, is an independent financial services company in which GM and private equity firm Cerberus Capital Management LP have smaller stakes.

The program, called Ally Brand Rewards after the banking unit of GMAC, will be administered through the auto unit. It offers cash-back and other incentives such as free access to services based on the volume of business within the product lines GMAC offers or the breadth of services, Mallino said.

The financial services company has multiple product lines that include financing for new and used vehicles, insurance products, vehicle remarketing services for dealers that want to sell vehicles they received as trade-ins to consumers or to other dealers, and wholesale financing of dealer inventories.

"We are looking to build long-term relationships with our dealers; that has been our strength and we want to continue to do that," Mallino said, adding that the dealership incentives have no impact on GMAC's consumer financing.

GMAC is the preferred provider of financing to purchasers of GM and Chrysler vehicles. It resumed leasing on GM vehicles in August and Chrysler vehicles in September.