Jon Symonds, who lost out in a 2005 race for the CEO job, is to leave at the end of July to join the investment bank as a managing director. The move is being seen as a blow to the drugmaker, which has suffered a series of setbacks with drugs under development and has struggled to regain investor confidence after its deal to pay $15.6 billion for MedImmune. The search for a successor is under way.

“I don’t think it will be very well taken, especially as (CEO Dave) Brennan has not gone down brilliantly. (Symonds) is still the face of AstraZeneca that people trust,” Paul Diggle, an analyst at Nomura Code Securities, tells Reuters. “On a more practical level, people may also wonder whether the regime of tight cost control that he has managed terribly well is going to be that easy to continue.”

Symonds joined Zeneca in 1997 and within months was involved in the merger negotiations with Sweden’s Astra. He quickly won respect from analysts and adopted a higher profile in running the business than many drug firm finance directors. “I regret Jon’s decision to leave AstraZeneca, however, the move to Goldman Sachs represents an exciting career challenge,” AstraZeneca Chairman Louis Schweitzer said in a statement.

The loss of a pivotal management figure may rekindle takeover speculation around AstraZeneca, Reuters reports. The company has long been seen as a possible target for larger rivals, who might be interested in acquiring its expertise in fields such as cancer medicine, despite the group’s weak pipeline of new drugs. Glaxo and Novartis have both been mentioned in the past as possible buyers, although the ceo’s of both have played down their interest in large takeovers in recent months.