DETROIT ? General Motors Corp. became the second major automaker in as many days to kick off contract talks with the United Auto Workers.

Ron Gettelfinger, UAW president, and Rick Wagoner, GM chairman and chief executive. shook hands and smiled Thursday afternoon in Detroit just as Gettelfinger and Chrysler chief Dieter Zetsche had done a day earlier in Auburn Hills, where DaimlerChrysler AG’s Chrysler Group is based.

The union was scheduled to start negotiations today with the third major U.S. automaker, Ford Motor Co.

Automotive suppliers Delphi Corp. and Visteon Corp. also are involved in negotiations, which both sides predict will be difficult.

The companies and the UAW will spend the next couple of months hammering out contracts covering wages and benefits for more than 300,000 workers. The pacts also cover pension payments and benefits for another 475,000 retirees and their spouses.

The current contracts expire Sept. 14.

Among other plants, GM operates an auto assembly plant in the Fairfax industrial district in Kansas City, Kan.