NEW YORK (Bloomberg) — A closely held firm run by Maurice (Hank) Greenberg, former chief executive officer of American International Group Inc., has created a new company that will sell health and accident insurance on behalf of Chubb Corp.The new unit, Starr Global Accident & Health Insurance Agency, LLC, is majority owned by Greenberg's C.V. Starr & Co. The unit will have headquarters in Greenwich, Connecticut, C.V. Starr said in a statement last week.