FALLS CHURCH, Va. – General Dynamics Corp.’s third-quarter earnings fell 2 percent due to continued weakness in the commercial aerospace and shipbuilding markets, and a significant charge in its marine systems unit.

The Falls Church defense contractor said Wednesday it earned $262 million, or $1.32 a share, in the quarter ended Sept. 28, down from $268 million a year earlier. General Dynamics is the parent company of Bath Iron Works, a Navy shipbuilder in Bath, Maine.

The company took a hit from a $45 million charge against commercial tankers in the marine systems group. The charge was partially offset by a $30 million tax credit in the quarter.

Sales rose 35 percent to $4.4 billion from $3.3 billion in the year-earlier period.