University of California faculty leaders voted Thursday to give professors more wiggle room to express their political and personal opinions in the classroom by revising the institution's 69-year-old academic-freedom policy, which had required instructors to be impartial and to give "dispassionate presentations."

The university system's Academic Assembly, meeting on the Berkeley campus, approved the policy by a 45-to-3 vote. Under the policy, faculty members will be able to reach definite conclusions in classroom discussions about politics. The policy notes, however, that "this does not mean that faculty are unprofessional," and it emphasizes that classroom discussion still "requires an open mind."

The change is an effort to bring the system's academic-freedom policy in line with those of other institutions, said Robert Post, a law professor at Berkeley who helped draft the revisions.

"The old statement of principles was so outlandishly disconnected to what university teaching is now that it made no sense to think about it that way," Mr. Post said.

The old policy instructed faculty members to "give play to intellect instead of passion" and to "stick to the logic of the facts." The policy was created during an anticommunist wave of the 1930s and "was basically an agreement between the State of California and the university that the state would stay out of academics and that the university would stay out of politics," Mr. Post said.

The university's president, Richard C. Atkinson, urged faculty members to revise the policy last year, after a graduate instructor warned in a course description that "conservative thinkers are encouraged to seek other sections." The statement caused an uproar and sparked debate about how far academic freedom should go, even though the policy's restrictions had been largely ignored by professors for decades.

The new policy will allow professors to teach about politics and to teach passionately, but it will not eliminate concerns that critics, such as the National Association of Scholars, brought up in debates before the vote. The critics worried, in particular, that professors could use the policy switch to begin indoctrinating students with their political outlook. But under the policy, "responsible instruction precludes coercing the judgment of a student, or the use of instruction as a means to nonacademic ends."

Mr. Atkinson still needs to approve the policy before it can go into effect, but his assent is expected.