Merrill Lynch & Co. is closing up to 10 offices nationwide because of slow business . . . Burlington Northern Inc. says the holding company will transfer its headquarters from Seattle to Ft. Worth by year-end. . . Citing losses at its FoxMeyer Corp. unit, Pittsburgh-based National Intergroup Inc. said it expects to report a net loss of $40 million to $50 million for its second quarter ended Sept. 30 . . . Alaska Airlines has been authorized by the U.S. Department of Transportation to serve the Mexican cities of Mazatlan and Puerto Vallarta from San Francisco.