French pharmaceutical company Sanofi-Aventis is preparing to make a major acquisition in the US in a deal that may be worth around $20 billion, Bloomberg reported yesterday.

Bloomberg, citing two of the people, who declined to be identified, said that Chris Viehbacher, CEO of Paris-based Sanofi-Aventis has briefed the board on possible acquisition targets in the US at a special meeting this week.

Although the French drug maker has yet not identified the target, sources told Bloomberg that the deal size could be as big as $20 billion.

As speculation mounted that Allergan Inc, Biogen Idec Inc and Genzyme Corporation would be the likely US pharmaceutical companies that would fit within the $20 billion deal size of Sanofi-Aventis, stock prices of these companies shot up in the US trading yesterday.

Allergan, based in Irvine, California is a specialty pharmaceutical company that develops and sells ophthalmic, dermatology and neurological products.

For 2009, it had revenues of $4.50 billion, net income of $621 million and has a market cap of $17 billion.

Cambridge, Massachusetts-based Biogen Idec is a biotechnology company specialising in drugs for neurological and autoimmune disorders and cancer.

It had reported revenues of $3.2 billion and net profit of $970 million for the fiscal year 2009. It market value is around $12.7 billion.

Genzyme Corporation also based in Cambridge, Massachusetts, is the world's third-largest biotechnology company and focuses on rare genetic disease disorders, renal diseases, orthopaedics, cancers, transplant and immune diseases.

It posted revenues of $4.5 billion and net income of $422 million last year. It market value is around $13.5 billion.

Sanofi-Aventis, the world's fourth-largest pharmaceutical company by prescription sales, is looking to make acquisitions since most of its patents will expire by 2013.

It has already made acquisitions worth nearly $3 billion this year including the $1.9 billion acquisition of US consumer healthcare products group Chattem Inc in order to strengthen its presence in over-the-counter (OTC) healthcare products in the US. (See: Sanofi-Aventis concludes Chattem acquisition)

Sanofi-Aventis, which had 2009 revenues of €29.31 billion in 2009 and a net debt of around $5 billion, has spent about $17 billion on 25 acquisitions since Viehbacher took over the reins of the company in 2008, according to Bloomberg data.