UPDATE 1-Sanofi to launch own generic version of Plavix

* Sanofi preparing to sell generic Plavix in France

* Sales via Winthrop unit part of corporate strategy

* Patents on drug ending in Europe, still valid in U.S.

(Updates with company comment, background)

PARIS/LONDON, Oct 5 (Reuters) - French drugmaker Sanofi-Aventis (SASY.PA) is preparing to sell its own generic version of the blockbuster heart medicine Plavix in France, a company spokesman said on Monday.

Plavix, known generically as clopidogrel and sold by Sanofi and Bristol-Myers Squibb (BMY.N), is the world's second biggest selling drug, with worldwide sales of about $9 billion. But it has recently lost patent protection in some European markets.

Asked about a report in La Lettre de L'Expansion magazine that Sanofi's Winthrop unit would start selling a generic version of Plavix as soon as this week, company spokesman Jean-Marc Podvin said: "We are preparing."

The decision to sell a generic form of the medicine is part of the group's strategy to retain at least some sales in the face of cut-price competition. It will also help build up Sanofi's important non-patented drugs business.

The European Medicines Agency earlier this year gave the green light to a number of generic versions of the blood thinner from generic companies including Acino (ACIN.S) and Teva (TEVA.TA), as well as Sanofi.

Acino, a generic drugmaker which was formerly known as Schweizerhall, has been selling generic Plavix in Germany since last year and the company said in January its generic version had already captured about a quarter of the German market.

Plavix is used widely in treating heart attack patients. It works in a similar way to aspirin by stopping platelets -- tiny blood cells vital for the normal clotting process -- from clumping together and forming life-threatening clots.

Eli Lilly (LLY.N) and Daiichi Sankyo (4568.T) recently launched a new branded rival to Plavix, called Effient, and AstraZeneca (AZN.L) hopes to win approval for its new anti-platelet drug Brilinta next year.

The widespread adoption of cheap generic Plavix will be a challenge for both these new drugs in the years ahead. [ID:nL1530044]

Plavix is set to face generic competition in the key U.S. market from 2012. (Reporting by Dominique Vidalon and Ben Hirschler; editing by Karen Foster)