Deliveries by Chicago-based Boeing Co.'s commercial jet business will fall sharply in 2002 and 2003 as a result of airline weakness following the devastating hijackings this week, two investment banks said Friday. Deutsche Banc Alex Brown analyst Chris Mecray said Boeing could lose at least 25 percent of its expected 2002 deliveries, slashing the total to 390 or lower from Boeing's forecast of 515. In 2003, deliveries could fall to 300 or lower, Mecray said, below his prior forecast of 470. Separately, Merrill Lynch analyst Byron Callan cut his 2002 forecast for Boeing jet deliveries to 456 and his 2003 forecast to 356. Boeing plans to deliver 538 jetliners in 2001 and has previously said it would deliver 510 to 520 in 2002. Franklin Park-based Dean Foods Co., a leading dairy processor and distributor, said its shareholders have approved the proposed merger between Dean Foods and Suiza Foods. Approximately 63 percent of the shares outstanding as of the record date were voted in favor of the deal. The merger also is subject to clearance by the Department of Justice.