Boston-Provincetown Airline filed Chapter 11.

The troubled airline is one of the nation’s largest regional carriers. Stephen Story, an attorney for Hugh C. Culverhouse, who holds a controlling interest in the Naples, Fla.-based airline, said the Chapter 11 petition was filed in U.S. Bankruptcy Court in Tampa at 5:03 p.m. EST, after normal working hours. The carrier was forced to file for protection because of “cash-flow requirements due to outstanding accounts payable,” Story said. But he added that “we will continue operations as usual.”