Sanofi-Aventis shares hit their lowest level in more than two years on Wednesday partly on worries over the possible exit of its main shareholders after it won a lawsuit over its Plavix blockbuster.
Analysts saw only limited upside for shares in the French drugmaker as oil company Total and cosmetics giant L'Oreal, which jointly own about 23 percent of Sanofi's share capital, made it clear they do not consider their stakes strategic.
Total has linked its 13.12 percent stake sale to the outcome of a US trial on Sanofi's bloodthinner Plavix and repeated on Wednesday it would sell its holding "soon". L'Oreal also stuck to its position, but said a sale was not imminent.
Sanofi shares fell 0.3 percent to 61.90 euros by 1131 GMT while the DJ health index was little changed. The stock has underperformed peers by nearly 10 percent this year.
"A further cap on the share price is likely to be the increased likelihood that major shareholders Total and L'Oreal ... now divest their stakes," Merrill Lynch said in a research note, rating the stock "neutral".
Sanofi shares briefly rebounded on Tuesday on a US court's verdict its Plavix patent is valid, but its victory against generic drugmaker Apotex rekindled speculation Sanofi could buy Bristol-Myers Squibb as a way to beef up its drug pipeline, which some analysts consider to be meagre.
Sanofi suffered a blow when a US healthcare panel last week unanimously voted against recommending its anti-obesty drug Acomplia for marketing approval on concerns it might be linked to suicidal thoughts.
The recommendation dented hopes Acomplia could be a blockbuster drug, making annual sales of at least $1 billion, to make up for treatments that will lose their patent protection. In a further setback, a Berlin court agreed with Germany's Joint Committee (G-BA), a self-regulating body of doctors and health insurers which makes drug recommendations, to classify Acomplia as a "lifestyle" drug and as such not to reimburse it.