DEARBORN, MICH. - Professors with tenure or who are on a tenure track are now a distinct minority on the country's campuses, as the ranks of part-time instructors and professors hired on a contract have swelled, according to federal figures analyzed by the American Association of University Professors.

Elaine Zendlovitz, a former retail store manager who began teaching college courses six years ago, is representative of the change. Technically, Zendlovitz is a part-time Spanish professor although, in fact, she teaches nearly all the time.

Her days begin at the University of Michigan, Dearborn, with introductory classes. Some days end at 10 p.m. at Oakland Community College, in the suburbs north of Detroit, as she teaches six courses at four institutions.

"I think we part-timers can be everything a full-timer can be," Zendlovitz said during a break in a 10-hour teaching day. But she acknowledged: "It's harder to spend time with students. I don't have the prep time, and I know how to prepare a fabulous class."

The shift from a tenured faculty results from financial pressures, administrators' desire for more flexibility in hiring, firing and changing course offerings, and the growth of community colleges and regional public universities focused on teaching basics and preparing students for jobs.

But it has become so extreme that some universities are pulling back, concerned about the effect on educational quality. Rutgers University in New Jersey agreed in a labor settlement in August to add 100 tenure or tenure-track positions. Across the country, faculty unions are organizing part-timers. And the American Federation of Teachers is pushing legislation in 11 states to mandate that 75 percent of classes be taught by tenured or tenure-track teachers.

Three decades ago, adjuncts -- both part-timers and full-timers not on a tenure track -- represented only 43 percent of professors, according to the professors association, which has studied data reported to the federal Education Department. Currently, the association says, they account for nearly 70 percent.

John W. Curtis, the union's director of research and public policy, said that while the number of tenured and tenure-track professors has increased by about 25 percent over the past 30 years, they have been swamped by the growth in adjunct faculty.

University officials agree that the use of nontraditional faculty is soaring. But some contest the professors association's calculation, saying definitions of part-time and full-time professors vary, and that it is not possible to determine how many courses, on average, each category of professor actually teaches.

Many state university presidents say tight budgets have made it inevitable that they turn to adjuncts to save money.

"We have to contend with increasing public demands for accountability, increased financial scrutiny and declining state support," said Charles F. Harrington, provost of UNC-Pembroke. "One of the easiest, most convenient ways of dealing with these pressures is using part-time faculty," he said, though he cautioned that colleges that rely too heavily on such faculty "are playing a really dangerous game."