C1 A.I.G . Officials Quit Starr Several top executives of American International Group , including the company 's current chief executive , resigned from C.V. Starr & Company , a private holding company run by Maurice R. Greenberg , who was forced out as the chairman and chief executive of A.I.G . C1 Chevron to Buy Unocal ChevronTexaco said it had agreed to buy Unocal , an independent American oil company , for $ 16.8 billion , expanding its global reach .