GREENBELT, Md. - A commercial general liability insurer has duty to contribute 50 percent of the $206,457.22 that a directors and officers liability insurer has paid in defending an underlying arbitration proceeding against mutually insured entities, a Maryland federal judge ruled April 21 (Federal Insurance Co. v. Firemen's Insurance Company of Washington, D.C., et al., No. 8:09-cv-02361-AW, D. Md., Southern Div.; 2014 U.S. Dist. LEXIS 54783).