A federal judge ruled Friday in favor of the union that represents most Metro employees in an ongoing wage dispute with the transit authority.

Amalgamated Transit Union Local 689, which has about 10,000 members, had been in arbitration with Metro over a 9 percent wage increase for its members to be awarded in 3 percent increments for 2009, 2010 and 2011.

“It’s a big win for us,” said Jackie Jeter, president of Local 689.

The case went before U.S. District Judge Peter J. Messitte. The dispute began in 2008 after the union and management reached an impasse on contract negotiations; the issue went to arbitration.

In November 2009, the arbitration board ruled on some issues for the union, but Metro appealed the decision.

Messitte’s opinion concurred with the arbitration panel.

Metro has set aside money in its annual operating budgets for a payout, according to Jeter and Metro officials.

Dan Stessel, a Metro spokesman, declined to discuss the case in detail. He wrote in an e-mailed statement: “We are reviewing the decision and will consider our next steps.”

Jeter said Metro could appeal Messitte’s decision.

“It is not rah-rah,” she said. “I’m not popping the champagne.”