Universities are as dependent on the Defense Department for research funding as they were at the height of the Vietnam war, largely because of federal spending on research for the Strategic Defense Initiative (SDI), according to a study critical of the program.

Sixteen percent of federally funded campus research is performed for the Defense Department, and defense spending at colleges has increased 89 percent since 1980, according to the newly released report, "Pentagon Invades Academia," prepared by the New York-based Council on Economic Priorities.

In 1968, during the the height of the Vietnam war, universities also received 16 percent of such funding from the Defense Department.

The Pentagon's slice of research spending at colleges, particularly in mathematics, computer science and certain engineering specialties, threatens to disrupt "the usual balance between civilian and military spending" while hurting other nonmilitary fields badly strapped for research funds, the report said.

Academia's deepening dependence on the Pentagon in general and SDI, also known as "Star Wars," specifically has sparked an intense 1960s-style campus debate on the role of weapons research at colleges, the future of academic freedom and the proper political role of scientists.

More than 2,400 scientists at 62 universities, including Nobel laureates and more than half of the physics faculties at several leading research schools, have signed petitions pledging not to take money involving SDI, President Reagan's space-based missile defense plan.

On the petitions, the scientists have called SDI technologically dubious and a threat to existing arms control agreements and free academic discussion. Boosters of SDI have tried recently to generate support for the program by working through campus Republican organizations and the conservative group, Young Americans for Freedom.

"We feel there's a real turnaround on college campuses," said Bruce Hallman, press director of High Frontier, a pro-SDI lobbying group.

The council report studied federal research contracts at 31 universities. Despite widespread opposition to SDI on some campuses, the report found, the Defense Department had no trouble finding takers for its research contracts.

Campus research funding from other federal agencies has not increased as quickly, the report said.

This "militarization" of federal research money "could hurt the nation's technological growth since developments in such critical areas as ultra high-speed computing, novel laser concepts and new micro-electronics devices will be dominated by military rather than civilian needs," said Alice Tepper, executive director of the council.