NATION

Robert B. Horton, vice chairman and chief executive of Cleveland-based BP America Inc., will leave that post in April and return to London to become a managing director of the company’s parent, British Petroleum Co. Horton, 48, also will become BP America chairman with responsibility from London for the U.S. arm of the company. He will replace BP Chairman Sir Peter Walters in that role. Horton became a director of Standard Oil Co. in 1983 and took on his present role when the company’s name was changed to BP America last July.

James Ross, 49, current chief executive and managing director of BP Oil International in London, will become BP America vice chairman and chief executive early in 1988.