If there were any doubt that health care was big business in the Lehigh Valley, a look at 2002's largest employers makes it clear.

Six of the top 25 largest companies are directly involved in health care, according to data compiled by The Morning Call. They include two of the top three employers, Lehigh Valley Hospital and Health Network, and St. Luke's Hospital and Health Network. Three other hospitals and national nursing home company HCR Manorcare also made the list.

Other 25-largest employers involved in health care include B. Braun Medical medical supplies and Aetna health insurance.

The dominance of health care on the local labor market is a trend that will continue as people live longer and baby boomers reach the age when they require more medical treatment, said Robert Zimmel, senior vice president of human resources for St. Luke's.

''It's a growing industry, and with the change in demographics the need for health care is going to increase,'' he said. ''We're hiring at a rapid pace. The economy has not had an effect on us.''

The Lehigh Valley 25 largest companies list measures employment in Lehigh and Northampton counties only. So, for example, employment at Agere Systems' plant in Reading is excluded. The list also excludes government agencies and public school districts.

Of course, a list of large employers doesn't mean what it once did. The Lehigh Valley labor market used to be dominated by large factories, but today, 43 percent of local employees work for companies with fewer than 100 workers. And about 25,000 people, almost 10 percent, work for companies with fewer than 10 employees, according to data kept by the Lehigh Valley Economic Development Corp.

But among the largest workplaces, health care dominates.

''We certainly feel that it's an honor to be the largest employer because that's also important for the economy of the area when employers are able to provide jobs,'' said Brian Downs, spokesman for Lehigh Valley Hospital. ''This is not something we planned. The community is entitled to the highest quality health care, and it's our mission to provide that care.''

LVH, as it's known, has reduced its operating costs by $100 million over the past eight years, without major layoffs, Downs said.

''Our work force has grown to meet the community's growing demand for our services.''

St. Luke's would actually move to No. 2 on the list if its other nearby facilities were added, including St. Luke's Quakertown Hospital. That would boost its employment to more than 5,000.

All local health care providers are likely to continue boosting their payrolls, especially for such jobs as nurses, pharmacists and radiology technicians, Zimmel said. ''It's hard to find good people, because the supply and demand don't quite match up at this point,'' he said.

The local hospitals are non-profit, except for Easton Hospital, which since mid-2001 has been owned by the for-profit Community Health Systems of Tennessee.

The largest for-profit company in the Top 25 is Air Products and Chemicals. At No. 2 overall, it employs more than 4,200 at its huge campus off Route 222 in Trexlertown. And that's not including its Hometown plant in Schuylkill County.

''Emerging as the largest for-profit employer in the Lehigh Valley is actually quite a heavy responsibility,'' said Leonard Broese van Groenou, Air Products' vice president of human resources. ''Although we are an international company operating in 30 countries around the world, we are headquartered here and are very conscious of the effect we have on this community.

''Air Products' success is closely linked with the success of the Lehigh Valley.''

He said Air Products' employment in the Lehigh Valley has been about the same for the past 20 years.

''Our business mix and the leadership positions we hold in many markets around the world have given us reasonable stability over the years,'' he said.