Sanofi ousts CEO after he warned of struggle ahead with diabetes drug in the US

French drugmaker Sanofi sacked its CEO Wednesday following a board room rift over the handling of one of France's largest publicly traded companies.

Christopher Viehbacher, the first non-Frenchman to lead Sanofi, was dismissed after six years running the company that traces its roots to the early 19th century.

In a statement announcing the ouster, Sanofi's board referred to the rift with the Canadian-German Viehbacher only obliquely, saying the company needs "a management aligning the teams, harnessing talents and focusing on execution with a close and confident cooperation with the Board."

Viehbacher, 54, will be temporarily replaced by Sanofi chairman Serge Weinberg, 63, the one-time head of Gucci parent company PPR who was himself ousted following a rift with his board.

Sanofi's shares more than doubled during Viehbacher's six years at the helm as he cut costs and shifted focus to biotechnology, vaccines and over-the-counter medications. He orchestrated the $20 billion takeover of U.S. biotech firm Genzyme in 2011. But his move earlier this year to Boston from Paris, where he'd moved after taking the helm at Sanofi, raised eyebrows in France.

On Tuesday, shares in Sanofi dived after the company reported a slide in quarterly earnings. Viehbacher said pricing pressure on its blockbuster diabetes treatment Lantus in the key U.S. market would continue to hamper sales growth into 2015.

Sanofi shares fell 3.7 percent to 71.85 euros early Wednesday following news of Viehbacher's dismissal.