General Motors Corp. delays the release of its second-quarter earnings by one week in order to calculate how its hourly-worker-buyout program will impact expenses and, ultimately the company’s bottom line.

The auto maker now is slated to announce its financial results July 26. That will be roughly one month after the deadline for hourly employees to decide on buyouts, intended to pare down the company’s manufacturing workforce.

So far, about 25,000 United Auto Workers union members at GM, and another 8,500 at Delphi Corp., have indicated they will take advantage of the compensation packages, UAW President Ron Gettelfinger said last week during the union’s annual convention in Las Vegas.

The auto maker is extending severance packages ranging from $35,000 to $140,000, depending on how long a worker has been employed with GM. The incentives are designed to bring down legacy costs and set the stage for closing or reducing shifts at 12 GM plants by 2008.

GM reported a first-quarter net income of $445 million, or $0.78 per diluted share, after revising its earnings in May. The profit came mainly through the sale of shares in several Asian auto makers, as well as from changes in how it accounts for health care for hourly employees.

Nevertheless, it was the first profit for the company in five quarters and compared with a loss of $1.3 billion, or $2.22 a share in like-2005.

Without giving specific guidance, GM Chairman and CEO Rick Wagoner recently said he expects restructuring plans will show benefits during the year’s second half.

Shares in GM rose 2.1% to $26.20 at the close of trading June 22.