Complex sentence: After the accidental drowning of his boss Édouard Michelin, he was appointed managing partner of the group in May 2007, also serving as head of financial affairs, legal services, plans and results.
Split into simpler sentences: After the accidental drowning of his boss Édouard Michelin, he was appointed to managing partner of the group in May 2007. He then also served as head of financial affairs, legal services, plans and results.