BUDAPEST, Jan 27 (Reuters) - European Union authorities gave the green light to the extension of car maker Audi's plant in the northwest Hungarian town of Gyor, Economy Minister Gyorgy Matolcsy said on Thursday. "We received news yesterday that the EU gave the green light to Audi's investment in Gyor and the requalification of a (nature reserve area) on the basis of public interest," Matolcsy told a news conference.