French drugmaker sanofi-aventis is reportedly considering making a higher offer for US genetics group Genzyme after the latter spurned its advances in August, and things could get hostile.

While a final decision is yet to be made, various media reports are citing sources close to the situation as claiming that sanofi may make a renewed bid for the group as early as next week, possibly raising its failed $69-a-share offer by $1 or $2.

The sources are reportedly also claiming that, while sanofi would prefer an amicable deal, the drugmaker is prepared to go hostile if necessary, perhaps signalling an intention to buy-in new products to help fill the revenue gap from looming generic competition to blockbuster blood thinner Plavix and other big earners.

In August, Genzyme unanimously rejected sanofi’s $18.50-billion takeover bid, which the latter claimed at the time represents a multiple of 36 times Genzyme’s 2010 earnings per share and 20 times analyst estimates for 2011 profits, and takes into account the upside potential of the US biotech’s anticipated recovery next year.

But the Genzyme slammed the proposal for being “opportunistic” and failing to recognise “the significant progress underway to rectify manufacturing challenges or the potential for [the firm’s] new-product pipeline”. The company said it was unprepared to enter into negotiations at an unrealistic starting price that “dramatically undervalues” its business.

Reuters quotes RBC Capital Markets analyst Michael Yee as noting that “a serious offer is more likely to iinduce improved conversations”, but that the firm would need to boost its bid into the $70s to get the ball rolling.