NEW YORK — General Motors Co. will reinstate 661 dealerships it sought to drop from its sales network.

GM executives said yesterday that the dealerships — more than half of those seeking to stay with the automaker — will receive letters giving them the option to remain open. GM said it would not have enough time to negotiate with all 1,100 dealerships that appealed the automaker's decision to close them within a four-month window imposed by the federal government.

"By doing this we save a lot of time, energy and dollars," said Jim Bunnell, GM general manager of network support, saying the company wished to avoid a "very large arbitration process."

As part of its restructuring, GM last year told about 2,000 dealerships it would not renew their franchise agreements once they run out in October 2010. But the dealerships have said GM treated them unfairly, and last month Congress passed a law requiring an appeals process for the dealers.

GM's decision to keep the additional showrooms open effectively shrinks the number of appeals it has to contend with. Arbitration hearings for the dealers who didn't get offers but still want to stay with GM will begin later this month.

The cuts to GM's 6,000-dealer network were designed to compensate for much lower demand for cars and trucks, but some dealers have argued that lots that are still profitable are at risk, and that the automaker hasn't offered enough details about how it's choosing which businesses to shutter.

GM would not offer any details yesterday about which dealerships it was reinstating and where they are located. It said it chose the 661 based on a variety of criteria, including sales and other business factors.

The company said it hoped to have every letter of intent with dealerships by Monday. Dealers have 10 days to respond and 60 days to meet a set of criteria that would allow them to stay with GM.

A spokeswoman with Chrysler Group LLC, which has cut 789 dealers, said the company was preparing a statement in response to questions about whether it also intended to reinstate dropped dealerships. Chrysler showrooms slated for closure are also appealing to stay open, though it remained unclear how many.

Congress-brokered talks between dealer groups and the automakers began in September. But those talks stalled over disputes about the review process for targeted dealerships and other issues.