May 14 (Bloomberg) -- MediGene AG, the German developer of the Endotag cancer drug, rose the most since 2004 on speculation that Pfizer Inc. may make a bid for the company.

MediGene gained 66 cents, or 12 percent, to 6.23 euros in Frankfurt electronic trading. The gain valued the Martinsried, Germany-based company at 211.5 million euros ($326.9 million).

``There is a rumor in the market that Pfizer is mulling a bid for MediGene, making the stock jump,'' said Thomas Nagel, a trader at Equinet AG in Frankfurt. Pfizer and MediGene have held talks over a possible takeover, Reuters said, citing industry sources.

Both MediGene spokeswoman Julia Hofmann and Pfizer spokesman Oliver Stohlmann declined to comment.

MediGene has been seeking a partner to bring the experimental Endotag treatment to market. The drug, which is being tested in a number of malignancies, may have an annual sales potential of 1 billion euros for pancreatic and breast cancer alone, the German company has said.

The drugmaker is looking for a strategic partner, and not to sell the whole company, MediGene Chief Executive Officer Peter Heinrich said in a Bloomberg Television interview in April.

To contact the reporter on this story: Eva von Schaper in Munich at evonschaper@bloomberg.net.

Last Updated: May 14, 2008 11:46 EDT