Shares in troubled German drugs company Bayer have risen amid strong demand for its anthrax treatment, Cipro.

Fears about the disease, which can be spread as a biological weapon, have grown since a Florida journalist died several days ago.

Bayer now plans to increase production of the drug by 25% from the beginning of November, resuming output at a plant which had previously been mothballed.

Other drugs companies have also benefited from the demand for vaccines to counter biological weapons.

Bayer boost

Shares in Bayer rose 2%, a small rise but a good result for a company that has been hit by a string of bad news.

The company was recently forced to withdraw its leading anti-cholesterol drug Baycol, and abandoned plans to list on the New York stock market.

Prior to the 11 September attack in the US, Cipro had been viewed as yet another concern for Bayer as its patent expires in 2004.

However, New Yorkers obtained 27% more prescriptions for Cipro in the final week of September than in the whole of last year, according to figures from the research company NDCHealth

"A lot of people are asking for it at the drugstore," a Bayer spokeswoman said, adding that stocks were running down quickly.

With worldwide sales last year of $1.6bn (�1.12bn), Cipro is the only orally administered drug recommended for such use by the US Centres for Disease Control and Prevention.

Drug boost

Other drug companies have also benefited from the crisis.

The UK's Acambis saw its stock leap nearly 80% on speculation the US government will bring forward orders for smallpox vaccine under an existing contract.

Shares in Cepheid, a company which manufactures systems designed to detect biological agents, rose 73% on Tuesday.