More than 20,000 blue-collar workers at General Motors Corp. have accepted buyout offers, surpassing the automaker's internal target, with a month to go before the deadline, the Detroit News reported on Thursday, citing people familiar with the situation.

The automaker, which made the offers to all 113,000 of its U.S. hourly workers, had expected 20,000 employees to come forward by the June 23 deadline, the sources told the newspaper.

GM will continue to offer buyouts to workers who sign up by the deadline as the automaker plans to take as many buyouts as it can get, the sources said.

A GM spokeswoman was not immediately available for comment.

GM shares rose more than 7 percent and its bond price got a slight lift on Wednesday after Merrill Lynch analyst John Murphy raised its rating on the automaker on signs that its cost-cutting program was moving faster than expected.

Murphy said there appeared to be significant interest in GM's buyout programs for its hourly workers represented by the United Auto Workers union, indicating progress in cutting GM's high labor costs.

The company is in the midst of a comprehensive restructuring, which includes closing a dozen plants and laying off 30,000 workers, to return its auto operations to profit.

GM's shares were up 2.6 percent at $27.2 in opening trading on the New York Stock Exchange.