The Franco-German group AVENTIS (turnover DM 4.4 billion for the first nine months of 2000) is to sell its 50% stake in the German silicon founder WACKER CHEMIE (turnover DM 4.86 billion in 1999 with over 17,000 employed) to the Wacker family. The latter, which holds half of the capital of this company, will take on the 50% held by AVENTIS by 2002. The financial terms of the operation have not been disclosed.