Bayer AG unveiled its official bid price for fellow German drugmaker Schering AG today of 86 cents per share. This means that the value of the offer now stands at 16.5 billion euros ($20bn, 200 million euros higher than original bid.

According to the company, the rise is down to Schering having issued shares to fulfil certain employee options, and that it would likely continue to do so throughout the offer period, which runs to May 31. An additional offer period may run from June 9 until June 22, as long as 75% have taken up the offer by the original deadline of May 31, the group said.

If the merger goes ahead as planned, the new entity would have its headquarters in Leverkusen and estimated annual revenues of nearly 15 billion euros, with the pharmaceutical operations combined into a new division - Bayer Schering Pharmaceuticals, which would be based in Berlin and have sales of around 9 billion euros. It would rank as the 12th-largest drugmaker.

The acquisition would be the largest ever undertaken by Bayer, which has been restructuring its business by spinning of certain chemicals interests into an independent company, Lanxess, and re-building the healthcare business in the wake of the damaging withdrawal of cholesterol-lowering drug Baycol/Lipobay (cerivastatin) in 2001.