French drugmaker Sanofi-Aventis could announce a deal to buy U.S. biotech Genzyme early next week if final negotiations between the companies go smoothly, Le Figaro reported on Thursday.

Sanofi will offer a minimum of $72 or $73 a share in cash, as well as a contingent value right (CVR) based on the performance of experimental multiple sclerosis drug Lemtrada worth between $2 and $5 a share, the newspaper said.

Genzyme has rejected Sanofi's initial $18.5 billion offer, worth $69 a share, which the French group has extended until Feb. 15.

Sanofi this week gained access to detailed financial information about Genzyme as the two agreed in principle on the terms of a takeover, raising expectations that a final deal can be hammered out in the near term.

Sanofi has agreed to raise its bid to the low $70s-per-share range, plus the CVR milestone payment, a source familiar with the situation said earlier this week, but it did not raise the offer as high as the $75 per share value Genzyme had sought.

The final valuation could be in the "very high $70s" including the CVR, a second source said.