US biotechnology firm Genzyme has turned down a $18.5bn �11.9bn; 14.5bn euros cash bid from French pharmaceutical group Sanofi-Aventis.
Sanofi made a formal approach to the US companys board on Sunday, only to have its interest spurned a day later.
In a letter to his French counterparts, Genzyme head Henri Termeer said the $69-per-share offer was too low.
It is unclear whether Sanofis management will now choose to make negotiate or make a hostile bid.
Sanofis interest in the US-based firm emerged earlier this month, but this is its first formal offer.
Genzyme, which employs about 11,000 people worldwide, researches treatments for a range of serious illnesses.
Observers had already expected Genzyme to hold out for a higher bid.
Sanofi is Frances fourth-largest company by market value.
If the deal went ahead, it may become the biggest corporate swoop on a US firm by a French group since media conglomerate Vivendis purchase of Seagram in 2000.
Posts
