In 1930, GM entered aircraft design and manufacturing by buying Fokker Aircraft Corp of America (U.S. subsidiary of Fokker) and Berliner-Joyce Aircraft, merging them into General Aviation Manufacturing Corporation. Through a stock exchange GM took controlling interest in North American Aviation and merged it with its General Aviation division in 1933, but retaining the name North American Aviation. In 1948, GM divested NAA as a public company, never to have a major interest in the aircraft manufacturing industry again. GM did, however, establish their own air transportation, with the creation of the General Motors Air Transport Section (GMATS).