The €7bn - €7.5bn (US$6.39bn - US$6.84bn) sale of the Aventis Crop Science business unit to German pharmaceuticals and chemicals group Bayer, may not be completed by the end of this month.

Klaus Pohle, CFO of Berlin-based Schering, holder of a 24% stake in ACS, told the Financial Times Deutschland, "the sale is unlikely to be completed in September," but added that it was still certain to go ahead.

Pohle did not say exactly how much Schering stands to gain from the sale, but commented that it could be between €1.5bn and €2bn. Schering will use the money in cooperations and acquisitions, particularly in the area of cancer research (oncology), and gene therapy.

Franco-German life sciences group Aventis holds the remaining 76% stake in ACS, and the sale is set to make both Aventis and Schering pure pharmaceuticals groups. Bayer will meanwhile become the second-largest agrochemicals specialist globally behind Anglo-Swiss company Syngenta.