Union leaders representing mechanics at Flyi Inc.'s Independence Air said yesterday that contract negotiations have bogged down, and they raised the prospect of a strike at the 31/2-month-old airline.

Officials at the Dulles-based carrier responded that negotiations are continuing with the assistance of a federal mediator, and the union cannot walk out even if it wants to.

Independence serves 38 cities from Dulles International Airport and plans to add more markets in coming months.

The airline inherited many of its employees from Atlantic Coast Airlines, which operated regional jet service for UAL Corp.'s United Airlines and Delta Air Lines Inc. It also inherited long-running labor negotiations.

"These negotiations have been going on for over two years." said Kevin Wildermuth, who chairs a negotiating committee for the Aircraft Mechanics Fraternal Association. "We want a contract, or we want the ability to strike, period."

The negotiations between the airline and the mechanics union are being mediated by the National Mediation Board. The union said it has asked the board for a release from the talks so it can strike. Independence said the union has no legal right to do so because talks are simply in a recess.

"The union is not in a legal position to strike," said Rick DeLisi, the airline's spokesman. "This might appear to look very serious and very significant. But I assure you it is not."

The federal mediator, Samuel Cognata, did not respond to a telephone message yesterday.

Airline industry analysts were divided over whether a strike by Independence's 340 mechanics could shut down the airline, which in August was filling 46 percent of its seats with paying passengers.

"This is hitting Independence at a very tough time," said Aaron Gellman, a professor and transportation expert at Northwestern University's Kellogg School of Management. "But I wonder if it's in the best interests of the mechanics to challenge Independence's management at this time. If it drives Independence out of business, where does that leave them?"

The starting base hourly wage for an Independence mechanic is $12.86, the union said. That compares with $16.42 for mechanics at Air Wisconsin Airlines Corp., another carrier that flies small regional jets, according to the union.

Mechanics at Southwest Airlines Co., which has a fleet of larger jets, have a starting base wage of $18.94 a hour, the union said.

The mechanics union at Independence is asking for a 30 percent average pay increase, according to Wildermuth. "But we're willing to negotiate," he said. Independence is offering about 4 percent, Wildermuth said.

DeLisi declined to discuss specifics of the negotiations.

Shares of Flyi Inc. closed yesterday at $4.04, up 4 cents.