PORTLAND (AP) — An ongoing labor dispute at Bath Iron Works, one of Maine’s largest private employers, has found a new battleground in U.S. District Court in Portland.

The Industrial Union of Marine and Shipbuilding Workers of America filed a lawsuit on behalf of its workers against the shipyard Wednesday, asking a judge to decide that their issue should not be settled by arbitration.

The Portland Press Herald (http://bit.ly/1bjrkTu ) reported that management at the General Dynamics-owned shipyard is attempting to reclassify workers’ jobs in hopes of landing a contract to build U.S. Coast Guard cutters, an initiative the company says relies on greater flexibility by management to assign workers.

Union president Jay Wadleigh says management is inappropriately trying to change the rules while an agreed-upon labor contract is in place.