GROTON, Conn. (AP) – Electric Boat says it will lay off 150 workers assigned to maintain the USS Philadelphia after the Navy shifted the maintenance contract to the Portsmouth Naval Shipyard in Kittery.

“Because we had factored this job into our business forecast, we’ll need to adjust the size of our work force to the lower workload,” John Casey, the Groton submarine builder’s president, said Wednesday.

The company, which employs about 7,000 people, had been working on a planning contract for the Philadelphia’s maintenance and repair work since June. Such planning work is typically a precursor to the actual maintenance work.

EB officials did not disclose the worth of the maintenance and repair contract. Navy officials were unavailable for comment, but EB spokesman Bob Hamilton said the company was told the decision was made “for the convenience of the Navy,” a standard line in contracts.

The layoffs will occur early next year, the company said.

The Philadelphia, which is based in Groton, returned to the base Wednesday after a five-month deployment marked by a Sept. 5 collision with a Turkish cargo ship in the Persian Gulf.

The planned maintenance and repair was not associated with the moderate damage done to the boat in the collision.

U.S. Rep. Rob Simmons, R-2nd District, criticized the Navy’s decision, saying it had an insufficient shipbuilding schedule and a shortsighted maintenance plan.

“It makes no sense for Portsmouth to hire new government workers,” he said, “and for EB to be forced to consider letting go already-trained private workers.”