Adjunct instructors at St. Paul's Hamline University, the first in Minnesota to form a union, have overwhelmingly ratified their first contract.

The deal, reached in December between the university and the Service Employees International Union Local 284 (SEIU), gives the instructors their first raise in 10 years.

In voting Friday, 95 percent of ballots were cast in favor of the agreement, which takes effect immediately with a 15 percent raise. The school's board also approved the deal last week.

In 2014, adjuncts at Hamline became the first in Minnesota to vote to unionize as part of a national campaign, called Adjunct Action, to improve wages and working conditions for part-time, temporary faculty on college campuses.

"We hope that our contract ratification, and the reality that our gains are locked in with a union contract so that they can't be taken away later, will help to inspire others to stand up and fight to strengthen higher education across Minnesota," said Mark Felton, a Hamline adjunct in the business school and member of the bargaining team.

The deal will increase the pay of about 200 Hamline instructors by 20 to 30 percent by the end of the three-year contract, according to the union. The university had paid the same base rate, $4,000 a class, for 10 years, said Della Zurick, a political science instructor at Hamline and a union negotiator. The two sides started negotiations in September 2014.

Hamline Provost John Matachek said Monday that university officials "are really pleased" with the outcome.

"Our goal really was to make sure we are all united in providing the best education for our students," Matachek said.

Typically, adjuncts are hired to teach specific classes and paid far less than tenured professors, with few if any benefits. The use of adjuncts has greatly expanded in recent years as colleges and universities have sought to rein in expenses and maintain flexibility in filling teaching slots.

Along with higher pay, other contract highlights include:

• A professional development fund.

• Earlier notice of what courses adjuncts will teach, and compensation if there is a last-minute cancellation.

• An option for adjuncts to teach courses they design or be compensated for the design.

Last month, faculty at the University of Minnesota filed for a union election with the Minnesota Bureau of Mediation Services. Organizers expect the union would number roughly 2,500 employees, including tenured and tenure-track faculty along with contingent faculty at the Twin Cities campus. If the organizing effort succeeds, the union would be one of the largest single-campus faculty unions in the country.