Bath Iron Works was awarded an $11 million contract modification to work on the maintenance system of littoral combat ships.

The shipyard, which has historically worked on destroyers and cruisers for the U.S. Navy, has been trying to diversify its product lines as the Navy changes the composition of its fleet. The $11,273,299 contract modification, made Tuesday to General Dynamics, the parent company of BIW, was awarded by the U.S. Navy’s Southwest Regional Maintenance Center in San Diego.

Littoral combat ships are smaller and more agile than destroyers and are designed for operations close to shorelines. LCS can be built for about $450 million, versus the $1.7 billion for Arleigh Burke destroyers. BIW has built more than half the Arleigh Burke destroyers in the Navy fleet.