Ford Motor said it has reached a...

Ford Motor said it has reached a preliminary agreement to sell its automotive paint operations to Du Pont for an undisclosed amount . . . Ceco Industries said a management group will present a $37-per-share buy-out proposal at a board meeting today . . . Security Pacific Corp. announced a 10.4% increase in the dividend on its common stock, raising the dividend to a quarterly 37 cents per share, payable May 20, to shareholders of record April 29 . . . K mart Corp. will ask its shareholders to approve staggered terms for its directors as a takeover defense at its annual meeting scheduled for May 27 . . . The Transportation Department said there are enough competitive questions about the proposed acquisition of Repubic Airlines by Northwest Airlines to warrant a formal hearing examining the impact of the merger. The department ordered oral arguments before an administrative law judge by June 27 to examine “the competitive and public-interest questions.”. . . Apple Computer said it is now selling its Macintosh 512K computer in an enhanced version, without a price increase . . . Wang Laboratories said it purchased for an undisclosed price its South Korean distributor, Computer Korea.