French drug maker Sanofi-Aventis has promised to take its acquisition bid for Genzyme Corp. to its shareholders, after Genzyme management dismissed its offer of $69 per share. Genzyme has said it will urge shareholders to reject the offer.

The company’s five largest shareholders, as of the end of June, included activist investors Carl Icahn and Ralph Whitworth. Whitworth’s company, Relational Investors LLC, owns 4.16 percent of the Cambridge-based biotechnology company’s shares, and Icahn Capital LP is listed with 4.11 percent of shares.


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Icahn’s ownership stake in Genzyme is far less than in some of his other portfolio companies. For instance, Icahn recently raised his stake in phone maker Motorola to 10.4 percent and upped his percentage of shares in Mentor Graphics to 15 percent. But Icahn’s interest in pushing for acquisitions and management coups extends to companies where he owns smaller stakes. For instance, Icahn owns 5.32 percent of Cambridge-based Biogen Idec and famously made waves in 2008 when he tried to put the company on the market, in opposition to company management.

Earlier this year, Icahn urged shareholders to oust Genzyme CEO Henri Termeer, blaming him for the ongoing manufacturing problems that have created shortages of two drugs, steeply eroding revenue.

Simos Simeonidis, a biotechnology analyst for investment bank Rodman and Renshaw, said that this type of posturing on both sides is fairly common in large-scale acquisition negotiations. He said it’s likely that Genzyme’s shareholders will hold out for a higher price.

“On one hand, Icahn wanted Termeer out – and I think Termeer will likely go whether a deal gets done or not. But that’s separate from the desire to get a higher price, so I assume Icahn would align with other investors and not settle on a price lower than $78 or $79 per share, or even up past $80,” he said.

Simeonidis said that while he expects a deal to go through eventually, it may take time. He said Sanofi likely needs the deal more than Genzyme, since Sanofi faces increasing competition from generics. He added that there are few other large-cap biotechs, with similarly deep assets, for the French drug maker to acquire.

No one investor has 5 percent or more of Genzyme¹s shares. Clearbridge Advisors LLC, with 4.83 percent of shares, is the company’s largest investor. Invesco Ltd. is the second largest, with 4.74 percent of shares.