Plessey Co. PLC, the British telecommunications giant, rejected a $1.74-billion takeover bid from General Electric Co. PLC, saying it was not in its shareholders' interests . . . Mary Kay Cosmetics Inc., Dallas, reported the completion of the leveraged buy-out of the company by an investor group led by Mary Kay Ash, its chairman, and her son Richard R. Rogers, the firm's president . . . Aetna Life & Casualty Co. said it plans to take an $89-million write-down in the fourth quarter to reflect the decline in the value of its investment in Gearhart Industries . . . Don C. Whitaker, a Pasadena businessman, reported in a Securities and Exchange Commission filing that he holds a 5% stake in Los Angeles-based Early California Industries' common stock . . . Western Airlines reported that it flew 692 million revenue passenger miles in November, down 3.3% from a year earlier . . . CBS Inc. reported the sale of its Holt General Book subsidiary, to Verlagsgruppe Georg von Holtzbrinck GmbH of Stuttgart, West Germany, for undisclosed terms . . . Leisure Technology closed $25 million in financing for its first retirement community with health related services, which is located in Lakewood, N.J.