Pharmaceuticals giant GlaxoSmithKline (GSK) has said profits grew strongly during the past three months, lifted by buoyant sales of its asthma drug Advair.

The company said on Wednesday that pre-tax profits for the three months to late June rose 7% on the year to �1.8bn, in line with analysts' forecasts.

Sales of Advair doubled to $416m during the period, making it GSK's's second biggest product just 15 months after its US launch, the company said.

It added that a 15% increase in total US sales also strengthened its bottom line, helping to offset the impact of the weak dollar on its sterling-denominated profits.

"In this challenging period for the pharmaceutical industry, GSK has produced excellent financial results," the company's chief executive Dr Jean-Pierre Garnier said in a statement.

City cheers

City investors appeared to agree, marking GSK shares 16 pence higher to 1073p in early afternoon trade.

Shares ended just two pence up on the day at �10.59.

GSK shares have lost more than a third of their value since the start of the year because of fears that recently-launched cheap generic or 'copycat' versions of some of its best-selling drugs will hit sales and profits in the months ahead.

News that three of the firm's top research scientists had resigned weigned on its stock last week.

There has also been speculation that the company, formed two years ago from a tie-up between the UK's Glaxo Wellcome and SmithKline Beecham, could be forced into further costly mergers or acquisitions in order to ensure future growth.

On Wednesday, the company said it expected growth in earnings per share - profits after tax divided by the number of shares in circulation - to fall to single digits next year, down from 13% during the latest three month period.

GSK is working on a number of new products which it hopes will become best-sellers, including erectile dysfunction drug Vardenafil - a potential rival to Viagra.