Various industrial businesses are located in Hannover. The Volkswagen Commercial Vehicles Transporter (VWN) factory at Hannover-Stöcken is the biggest employer in the region and operates a huge plant at the northern edge of town adjoining the Mittellandkanal and Motorway A2. Jointly with a factory of German tire and automobile parts manufacturer Continental AG, they have a coal-burning power plant. Continental AG, founded in Hanover in 1871, is one of the city's major companies, as is Sennheiser. Since 2008 a take-over is in progress: the Schaeffler Group from Herzogenaurach (Bavaria) holds the majority of the stock but were required due to the financial crisis to deposit the options as securities at banks. TUI AG has its HQ in Hanover. Hanover is home to many insurance companies, many of which operate only in Germany. One major global reinsurance company is Hannover Re, whose headquarters are east of the city centre.

Answer this question, if possible (if impossible, reply "unanswerable"): Who holds minority stock in Continental AG?
unanswerable