General Motors Corp. is beginning a three-year cost-cutting plan that includes urging U.S. suppliers to ship their work offshore.

The plan, expected to be unveiled Sept. 20, follows the completion of a separate three-year program aimed at reducing by 20 percent its $85 billion global purchasing bill as rancor among suppliers over the automaker's cost-cutting demands is reaching a fever pitch.

Bo Andersson, GM's purchasing chief, expects the plan to provoke many of GM's 250 top suppliers.

I see much more emotion in our supply base and non-professional businessmanship in the last two years than I've seen in my whole career, he said.

Still, GM is under pressure: It has lost $2.5 billion in North America this year and is pressing the United Auto Workers to consider higher out-of-pocket healthcare costs.