PARIS, Dec 12 (Reuters) - Former Wyeth chief executive Bernard Poussot looks to be out of the running to take over as the next boss of French drugmaker Sanofi, as Swiss rival Roche said on Friday he was joining its board.

Poussot, who was schooled in Paris and ran the U.S. pharmaceuticals group before it was acquired by Pfizer in 2009, was seen by some analysts as a potentially good choice to run Sanofi.

Sanofi has been hunting for a new boss since the October ousting of Chris Viehbacher as CEO, following a clash with the board over his management style.

Sanofi's chairman, Serge Weinberg, who has taken the helm in the interim, said last week that France's high tax burden made it hard to recruit top executives, although he declined to comment on individual candidates for the job.

Weinberg has said he will look for the best candidate, irrespective of nationality, but most industry observers believe the right person will at least have to be fluent in French.

Olivier Bohuon, chief executive of medical devices maker Smith & Nephew, has also been tipped as a frontrunner for the post but people familiar with the matter said he told staff last month he had no plans to leave the British firm.

Other names floated by industry observers include Olivier Brandicourt, head of Bayer's healthcare business, and Christophe Weber, president of Japan's Takeda. Pascal Soriot, the chief executive of AstraZeneca has also been suggested by industry observers as a potential candidate but is not expected to be interested.

Sanofi declined to comment on the succession process on Friday.

(Reporting by Ben Hirschler and Natalie Huet; Editing by Greg Mahlich)