The United Auto Workers said it plans to launch an effort to rally stockholders to oppose executive bonuses at General Motors at a time when the giant auto maker's profits are slumping . . . Combustion Engineering launched a $35-a-share, $147-million tender offer for Accuray Corp. of Columbus, Ohio . . . Southern California Water Co. offered 560,000 common shares at $28.25 each through E. F. Hutton & Co. and Kirkpatrick, Pettis, Smith, Polian Inc.