Nathan’s appointment becomes effective on October 1, Sanofi Romania said in a statement Tuesday. He will also be Chairman of the Board at Zentiva S.A. (SCD.RO), a unit of Sanofi.

Nathan has been working with Sanofi since 1996. In 2008, he was appointed General Manager of MCO Danube, which includes the company’s units in Bulgaria, Moldova, Romania and Hungary.