In 1971 the company merged with Österreichische Automobil Fabriks-AG (ÖAF) to form ÖAF-Gräf & Stift AG, which in turn was taken over by MAN AG the same year. ÖAF-Gräf & Stift AG continued manufacturing under that name, as a subsidiary of MAN. Still based in Vienna, it was focused on supplying trucks and buses for the Austrian market, mostly based on MAN designs, and additionally specialised in trolleybuses. It was MAN's main trolleybus producer in the 1980s and 1990s, and these were sold under the Gräf & Stift name, with trolleybuses being supplied to several European cities, including Salzburg, Solingen and Bergen (Norway), among others.