The union representing nearly 30,000 teachers in the nation's largest public university system said Tuesday that its rank-and-file members have overwhelmingly approved a new, three-year contract that grants raises totaling 10.5 percent over the next 14 months.

The deal still must be approved by the California State University Board of Trustees, which is expected to take it up at its May 24-25 meeting.

The California State University Faculty Association said 63 percent of its 28,000 members cast ballots last month, with 97 percent voting in favor.

The proposed deal, reached by negotiators for both sides, headed off a threatened five-day work stoppage by teachers at the CSU's 23 campuses, which enroll a total of 474,000 students.

It would grant faculty members a 5 percent raise on June 30 and another 2 percent raise the following day. That would be followed by a 3.5 percent raise on July 1, 2017.

It would also extend from five years to 10 the time it takes a newly hired faculty member to become tenured. That new tenure requirement would begin in Fall 2017.

Chancellor Timothy White has said the tentative pact is expected to cost the CSU system an additional $200 million.

He said money the university didn't spend on faculty raises this year while contract negotiations dragged on, plus funds it had already budgeted for raises next year, would cover more than half that cost.

White said CSU and union officials would have to lobby the state Legislature and the governor for the rest of the money.

"This dispute was an unfortunate symptom of a core problem in California, which is that the California State University and for that matter the University of California are underfunded relative to the state's need for an educated populace," White said last month after the tentative deal was reached.