OAKLAND -- Port of Oakland commissioners approved a contract with four unions that keep the fifth busiest harbor and the Oakland International Airport running.

The 6-1 vote Thursday afternoon ended a stalemate with Service Employees International Union, Local 1021, that began in earnest in March when SEIU members rejected an earlier contract.

The impasse dragged on until late November when the union staged a one-day strike at the port. Mayor Jean Quan and incoming Deputy Mayor Sandré Swanson persuaded the two sides to reconsider.

The result is a contract that keeps a controversial pension contribution but gives workers raises equal to the giveback in the first year and a ratification bonus of $3,500 for the more than 400 workers in four bargaining groups at the airport and harbor. In addition to SEIU 1021, they are the International Brotherhood of Electrical Workers, Local 1245; International Federation of Professional and Technical Engineers, Local 21; and Western Council of Engineers.

The port expects to save $14 million over the next decade and another $5 million between July 1, 2011 to June 30, 2015 in part by getting members to agree to changing the number of years new hires have to work before they get full medical coverage from five to 20 years.

"That's a big savings for us, but it's out in the future," Commissioner Earl Hamlin said.

Board President Gilda Gonzales voted against all four agreements.

Now, even as the Port resolved one labor dispute, another threatens to flare up.

About 134 concession workers at the Oakland airport are prepared to strike as early as Friday against HMSHost, the company that runs concessions at the airport through a contract with the Port.

HMSHost wants employees to pay for family medical cost increases, Unite Here organizer Lian Alan said Wednesday. Meal breaks would be unpaid and wages would be frozen for the length of the contract, he said.

The top wage for an airport food service worker is about $15.75, but many earn between $8 and $12.99 an hour. Union workers were willing to take lower wages for better benefits including full health care coverage, Alan said.

Unite Here members plan to rally at noon and 6 p.m. outside the airport's terminals any day that workers are on strike.

In addition to the SEIU and Unite Here matters, about 100 workers employed by subsidiaries, including Jamba Juice, Burger King and Subway, filed complaints with the National Labor Relations Board and the port charging the companies with union busting and living wage violations.

HMSHost did not return calls for comment.