Mukesh Ambani retains his title as India's richest person for the ninth consecutive year despite his wealth dropping by $4.7 billion. His Reliance Industries, hit by lower oil prices, saw shares tumble on falling revenues, which declined by close to a fourth in the latest quarter. It sold its stake in a U.S. gas pipeline unit for $1 billion in July and is now preparing for the imminent launch of 4G services by telecom arm Reliance Jio. Wife Nita, who sits on Reliance's board, is involved in Jio's marketing plan. Reliance owns Network18, a licensee of Forbes Media.