A bid by Sanofi-Aventis for Bristol-Myers Squibb could still be in the offing but the two men at the held of the Franco-German drugmaker are reported to be in disagreement as to the benefits of such a move.

Quoting banking sources, The Times claims that a boardroom split has emerged at Sanofi over a possible $54 billion deal to acquire B-MS with chairman Jean-Francois Dehecq backing a bid, while chief executive Gerard Le Fur prefers to concentrate on organic growth.

The rumour mill suggested that talks of a potential link-up between Sanofi and the US drugmaker, with which it jointly co-markets the blockbuster blood-thinner Plavix (clopidogrel), had been called off last month over disagreements of valuation but the newspaper is saying that it could be back on, despite the “significant difference” in tactics being adopted by the men, which has led to friction over the direction of the group.

Mr Dehecq is said to favour a "transformational" deal, while Mr Le Fur believes Sanofi should focus on internal drug R&D. "It's a question of ego rather than the timing of any deal," one of the Times sources is quoted as saying, adding that the chairman’s view is the more likely to prevail because he wields greater authority in the boardroom and among big shareholders, such as the oil group Total and cosmetic company L’Oreal.

The newspaper says that a bid for B-MS is unlikely before outstanding litigation over Plavix has been settled. The case revolves around a patent deal struck with Canadian generic drugmaker Apotex, which then flooded the US market with copycat versions of the drug last summer, wiping out over 60% of Plavix sales. A final judgment in the lawsuit could come as early as the end of April.

Sanofi denied that there was any difference in strategy between the chairman and the CEO, while Bristol-Myers Squibb declined to comment on the possible deal which would create the largest pharmaceutical company in the world, worth some $175 billion.

FDA advisory meeting for Acomplia on June 13

Meantime, Sanofi shares slipped slightly as the company announced that a US Food and Drug Administration panel is to meet on June 13 to cast an eye over the firm’s obesity drug Acomplia (rimonabant). The agency’s Endocrinologic and Metabolic Drugs Advisory Committee will meet that day to discuss the efficacy and safety of the drug in a move that some observers fear casts further doubt on whether the agency will back the treatment.

Last month, the FDA extended its review period yet again on Acomplia until July 27, after it had been expected to give its verdict in April after it accepted Sanofi's New Drug Application resubmission for the treatment in December. The firm seems untroubled about the June meeting, however, and said it is “pleased to have the opportunity to present its data on rimonabant and to exchange with experts.”