Union members nearly unanimously ratified eight-year contracts Friday afternoon, officially ending a three-week strike and one of Yale’s most protracted labor disputes.

Members of locals 34 and 35, the clerical, technical, service and maintenance workers’ unions, will return to work Sunday and Monday. About half the members of each union voted on the packages at membership meetings Friday, where they nearly unanimously approved the contracts and expressed relief at the settlement. Local 35 members voted 535-11 for the deal, while Local 34 members approved the contract 765-10.

The eight-year contracts — the longest in Yale’s history — were tentatively settled Thursday after 19 months of bargaining. The previous contracts expired in January 2002, though they were extended monthly until last March. Workers have not received raises since February 2001.

Union members, who chanted “V-I-C-T-O-R-Y” as they walked into their respective membership meetings, said they were pleased with the new contracts.

Bob Scott, a cook at the Hall of Graduate Studies, said he was glad to return to his job under a reasonable contract.

“I’ve been employed here almost 24 years, and it’s the best contract and the best support [Local 35 has] ever gotten,” Scott said.

The contracts, which will expire in January 2010, will address both the University’s call for a lengthier contract term and the unions’ demand for better pensions.

The agreement nearly doubles monthly pensions by raising the typical pension multiplier from about 1.08 to 1.48. The pension multiplier, which takes into account years of service and salary at retirement age, will be 1.5 on the first $30,000 of final salary, 1.4 on the next $25,000 and 1.3 on salary above $55,000.

Workers will also receive across-the-board raises by January 2009 that will total 43.6 percent for Local 34 and 32.3 percent for Local 35.

Under the accord, union members will earn retroactive pay equal to two-thirds of the amounts due to them, with a minimum payment of $1,500. The average retroactive compensation will add up to over $2,500.

Yale officials said they were optimistic that the two sides could work towards a better relationship over the next eight years.

Yale’s chief negotiator, Brian Tunney, the University’s director of labor relations, said the contracts mark the first time that Yale and union negotiators have worked out a plan that will take specific steps to improve the two sides’ tumultuous relationship. The University will provide $200,000 to begin a program that addresses best practices.

“We got a framework where, if both sides apply themselves, we can actually accomplish something,” Tunney said.

Local 35 President Bob Proto agreed.

“If we do the work in this contract, we can avoid a repeated cycle of banging our heads against each other,” Proto said.

As union members return to work next week, Yale administrators are preparing to help union members and students adjust. Full dining hall service will be restored beginning with breakfast Monday, Yale College Dean Richard Brodhead wrote in an e-mail to undergraduates Friday afternoon.

Interim Associate Vice President for Administration Janet Lindner said University officials will hold discussions with managerial and professional staff members on how to welcome back workers. She said the administration will also work with union leadership to help union members settle back into their jobs.

But some Local 34 members who went on strike said they anticipated some awkwardness when returning to work, since a large portion of the union — 65 percent by University estimates; 40 percent according to the unions — did not strike.

Elizabeth Johnson, who works at Sterling Memorial Library, said some union members are resentful that workers who went to their jobs during the strike will receive the same contract benefits as those who participated in the walkout.

“There’s a lot of anger,” Johnson said. “If we got this good a contract with one-third to one-half of the people out, we could’ve maybe done better or had a shorter strike.”

With contracts settled, leaders for locals 34 and 35 said they will turn their attention to helping 150 dietary workers at Yale-New Haven Hospital, who are also on strike and still do not have contracts.

— Staff Reporter Philip Rucker contributed to this report.