NEW YORK (AP) Bermuda-based Aspen Insurance Holdings Ltd said yesterday that chief financial officer Richard Houghton is resigning as of February 29.The company said Mr Houghton is leaving to pursue other opportunities. He will file Aspen’s annual 10-K for 2011 before his departure.Julian Cusack, the company’s chief risk officer, will be acting CFO while the company looks for a replacement. Mr Cusack served as CFO from the company’s founding in 2002 until April 2007.Shares of the insurer fell 39 cents, or 1.4 percent, to $27.75 in New York trading yesterday.