Unions at Sanofi-Aventis have called on staff in France to strike on Wednesday to fight plans to cut jobs at the French drugmaker.

A group of nine unions representing staff at Sanofi said the company was seeking to scrap 916 jobs, adding that 2,700 jobs had been cut at the company since the fusion between Sanofi and Aventis in 2005.

"The reality is that these job cuts are part of a vast 2 billion-euro savings plan that group management wants to achieve by 2013. All the group's businesses are affected," the unions said in a statement on Tuesday.

A spokesman for Sanofi said the group had not announced any new job cuts since unveiling a reorganization of its French commercial division last month which would lead to 575 out of 2,800 jobs going by the end of this year.

The spokesman said the unions had reached the figure of 916 by adding to this 260 unoccupied posts and 81 staff who will be expected to change role.