A Business School professor is leaving Harvard to become the first vice chairman of Union Pacific Corporation, one of the largest railroad and oil concerns in the world.

John R. Meyer, professor in transportation, logistics and distribution, will assist the chairman and the president of Union Pacific in the general management of the company, and will develop an in-house economic staff to do short-term forecasting and longer term trend evaluation, Harvey Turner, director of public relations at Union Pacific, said last week.

Meyer, a member of the Union Pacific Board of Directors since 1978, plans to take a two-year leave of absence from Harvard, where he is a member of the Economics Department and the Kennedy School. "I have not had a sabbatical in a long time and will welcome the change. If this turns out to be the end of my career at Harvard, it will definitely be with certain regrets," Meyer said last week.

Meyer, who has been writing about government transportation policy for 25 years, added, "There is nothing negative at all about my leaving. It is the challenge of becoming involved in an intimate way with the problems I have been writing about for years."

Union Pacific is currently involved with two mergers, and Meyer's basic theory is that railroad service can best be improved by "end-to-end" mergers as opposed to "parallel" mergers.

Harvard professors yesterday lauded Meyer's talents in the transportation area. "John Meyer is one of the strongest people in the country in areas of transportation and logistics, and he is one of the distinguished members of the faculty," John V. Lintner, professor of Economics and Business Administration, said yesterday.

"There are other people in his area, but his absence will leave a hole," John F. Kain, professor of Economics and City Planning, said yesterday.