Updated from 11:51 a.m.General Motors ( GM) began a round of layoffs for hundreds of salaried employees as the company works to offset plunging sales, dwindling market share, spiraling costs and a host of other issues. GM spokesman Robert Herta confirmed Tuesday the world's largest automaker is laying off hundreds of salaried workers at a variety locations across the U.S., but he declined to provide further detail. The company has said it plans to cut 7%, or thousands, of its 36,000 salaried employees this year, which suggests deeper cuts lie ahead for the automaker. GM, which posted a loss of $10.6 billion for 2005, is trying to pare down its cost structure as its market share shrinks under competitive threats from foreign-based auto manufacturers such as Toyota ( TM). Last fall, it unveiled sweeping restructuring plans that called for laying off 30,000 U.S. hourly workers and closing 12 facilities by 2008. Last Wednesday, the company said it plans to offer buyout packages to its 113,000 hourly workers in return for early retirement. Shares of GM were recently up 18 cents, or 0.8%, to $23.11.