As the company's annual two-week shutdown began, GM and the United Auto Workers talked just under four hours at the Flint Metal Center, company spokeswoman Mary Irby said.

Talks lasted about 4 1/2 hours at the Delphi Flint East plant. Industry analysts estimate the strike is costing the No 1 automaker more than $75 million a day, putting it on track to become the worst labour battle at GM in nearly 30 years. The strike by 9,200 plant workers has idled 162,600 workers. The domino effect of the work stoppage has forced the shutdown of more than 100 parts factories and all but three assembly plants. Still operating are a truck plant in Oshawa, Ontario, in Canada; the Saturn plant in Spring Hill, Tennessee; and a small car plant in Ramos Arizpe, Mexico.

The strike has pressuredthe automaker to begin trying to cut costs. The annual summer shutdown normally would amount to a paid vacation for most union employees, while some skilled trades and maintenance workers usually remain to do annual maintenance and update the assembly lines.

But GM said it has told all manufacturing plants affected by the strikes to go into "cold shutdown" mode - halting activities other than manufacturing, such as non-essential repairs and maintenance - to save money. The company has also said it will slash spending on advertising through the end of July.GM went on the offensive Wednesday, accusing the UAW of waging an illegal strike and threatening to withhold unemployment benefits for the workers idled by the walkout. The UAW legally has the right to strike only on issues related to worker health and safety and over-production standards.

Although the major issues at the Flint Metal Center are job security and commitments for future investment, the union has said its grievances cover safety andproduction standards. Striking workers are paid $150 a week by the UAW as long as they spend at least four hours picketing. Workers from other plants that are idled because of the strike can file for state unemployment benefits.