DRUGS company GlaxoSmithKline said yesterday that it was accelerating preparations to supply a vaccine against bird flu in the event of a pandemic.

Europe's largest drug maker said it was converting some of its factories to increase the production of a pandemic flu vaccine and was developing a prototype shot against the H5N1 strain of flu that has already killed about 60 people in Asia.

But the company said that its factory in Barnard Castle, County Durham, which employs more than 1,000 people, would not be one of those being converted.

Glaxo said it would be ready to trial the jab against bird flu before Christmas and, if the tests were successful, the firm would immediately file for regulatory approval for the vaccine to be given.

The company also plans to increase output of the anti-viral drug Relenza and has decided to allow other pharmaceutical firms to make it for free. Relenza is not a cure but reduces the severity of influenza and gives people a much greater chance of survival. It is similar to the Tamiflu treatment of Swiss firm Roche, which has seen sales spiral

However, chief executive JP Garnier said it could take as long as six months before stockpiles of the Relenza drug were large enough to meet demand.

He said: "It's clearly not business as usual for Glaxo. We are pulling out all the stops to do everything we can to be ready and help various governments to have their planning in place if there is a catastrophic event such as a global pandemic.

"If it happens tomorrow, it would take four to five months, maybe six months, before substantial quantities of the drug would become available."

Glaxo yesterday posted its third-quarter results, announcing a 21 per cent rise in pre-tax profits to £1.75bn.

Among its top performing products, sales of its asthma drug Advair rose 20 per cent to £737m, while diabetes drug Avandia saw sales rise 22 per cent to £355m. The group's vaccines business continued to perform well with sales up 20 per cent to £399m during the quarter. Glaxo recently invested £1.1bn in expanding its vaccine manufacturing.

Overall, turnover rose 11 per cent to £5.47bn.