General Motors Corp. (GM) declined to provide a production estimate for the third quarter citing its continuing bankruptcy process.

The auto maker is in the process of selling three of its brands, which could affect plant output, said GM's sales analyst Mike DiGiovanni. GM is working to sell Hummer, Saturn and Saab.

"We expect that once the sales close we will be in a position to provide this figure, we just think that where we are right now in the court sales process, not coming out with a number right now is probably the prudent thing to do," DiGiovanni said.

GM filed for bankruptcy June 1 after failing to orchestrate an out-of-court business restructuring that met federal government expectations. GM is in the process of breaking itself into two companies in which the underperforming assets will be liquidated.

Competitor Ford Motor Co. (F), meanwhile, boosted its third-quarter U.S. production target for a second time earlier this week.

The company intends to build 485,000 new cars and light trucks during the quarter, a 16% increase over the 418,000 produced in the year-ago quarter.

The move marks the first time in two years that Ford's quarterly production will be increased year-over-year, and comes amid fresh signs that the downturn in U.S. auto sales may be abating.

-By Jeff Bennett, Dow Jones Newswires; jeff.bennett@dowjones.com; 248-204-5542