(FORTUNE Magazine) – Executives aren't cutting classes even though times are tight. Over 15,000 of them will be attending a variety of business-related programs at North American colleges in 1991, 10% more than last year.

The price? At Columbia University's B-school, where the enrollment for executive courses is already up 21% this year over last, companies like AT&T, General Electric, and Nynex pay $4,500 per head for employees to attend professor Anna Duran's one-week course on managing cultural diversity. Northwestern's Kellogg school charges $12,500 per head for a four-week program taught by several professors. Customers include Boeing and Eastman Kodak. Rather than picking off-the-rack courses, some companies order ones that have been tailor-made. At Wharton these cost an average $15,000 a day. Room and board are extra. Du Pont is dispatching seven groups of 35 executives for instruction on managing shareholder value. There's little free time for the students. Says Charles Cantwell, a Du Pont senior financial analyst who helped develop the course: ''These professors don't give you a break. Classes start at 8 A.M. sharp and run till 5:30. Then we have two hours of homework. You don't come here to play golf.'' - K.B.