General Electric Co.'s plans to increase employee health-care costs further in June could result in a nationwide strike, the president of the company's biggest union said ahead of a two-day walkout set to begin Tuesday.

"If we don't stand up to them now, they're going to think they're 'James Bond: licensed to kill' come June and they'll have more serious demands on the table, " Edward L. Fire, president of the International Union of Electronic Workers-Communication Workers of America said at a news conference.

The union's national contract expires June 15.

"We've had several years of successful negotiations with our unions," company spokesman Gary Sheffer said. "We will discuss these issues with them at the bargaining table as we always have."

Fire said he received a letter from a vice president in GE's human resources department, whom he didn't identify, that said the company intended to impose additional increases. Sheffer said he wasn't aware of any such letter.

The company's right to implement higher health-care costs and the union's right to strike in protest were negotiated in their last contract. GE has said its health-care costs rose 45 percent to $1.4 billion in 2002 from $965 million in 1999.

The scheduled walkout by 17,000 employees, about 5.5 percent of GE's workforce, was called to protest health-care increases imposed on Jan. 1. It would be the first national strike at the company in 30 years. The strike would affect 48 plants and offices in 23 states, including businesses that make lighting, engines, appliances, motors and plastics.

GE said the Jan. 1 increase will remain. Employees will pay about $200 a year more for health care, GE has said. The union estimates the increase at closer to $400.