Sanofi shares down despite $13 billion Regeneron payday

PARIS (Reuters) - Shares in Sanofi fell on Tuesday despite the French drugmaker's impending $13 billion (£10.56 billion) payday from selling most of its 20.6% stake in U.S. partner Regeneron .By 1111 GMT, shares in Sanofi were down 1%, in line with the broader European health index .The stake sale, part of a major overhaul under new CEO Paul Hudson, will see Regeneron repurchase $5 billion of its stock with the rest set for a public offering. Sanofi will keep some 400,000 Regeneron shares -- a..