GlaxoSmithKline this morning announced that its next in line to the chief executive throne is Andrew Witty, who will succeed Jean-Pierre Garnier when he retires at the end of May 2008.

GSK has gone through a major process to single out a new CEO from a clutch of three hopefuls – the other two being David Stout, president of pharmaceutical operations and Chris Viehbacher, president of the US pharmaceuticals division. The firm’s chairman Sir Christopher Gent said that fact they had been able to select from three strong internal candidates is “testament to the quality of management at GSK.”

Witty was named President, Pharmaceuticals Europe for GlaxoSmithKline in January 2003 having joined GSK back in 1985. Prior to his current role he held the post of Senior Vice President, Asia Pacific.

When he retires next year, Garnier will have been in the CEO role since 2001, taking over from Sir Richard Sykes who moved on to become Rector at Imperial College London. Garnier has steered the firm through the sometimes tricky merger between Glaxo Wellcome and SmithKline Beecham, but it is perhaps not quite the steady ship he may have hoped to hand over after concerns about links to cardiovascular disease for its top-selling diabetes drug Avandia (rosiglitazone) triggered a massive decline in the product’s sales – tumbling 22% during the three-month second quarter of this year to £349 million.

Overall revenues in the second quarter rose 3% to £5.67 billion as old faithful Advair (fluticasone and salmeterol) continued its advance in the market place bringing in £871 million (up12%) and analysts were cheered about a slew of new product hopefuls, including the breast cancer drug Tykerb (lapatinib), the anti-infective agent Altabax (retapamulin) and the cervical cancer vaccine Cervarix, which has just been launched in the UK.

Analysts are, however, already speculating about the future of Stout and Viehbacher. Both could now leave the firm after being passed over for the top job.

Garnier had originally been expected to retire this year when he turns 60, but his contract was extended to oversee the launch of new medicines in its now burgeoning portfolio.

Shares in GSK dropped marginally on the London Stock Exchange this morning as investors appeared to be keeping cool about the announcement.