Mikhail Prokhorov is probably best known for standing unsuccessfully against Vladimir Putin for the Russian presidency in 2012. He made his fortune first as chair of Onexim Bank in 1990s, and then as chief executive of a metals firm his bank helped to privatise. Prokhorov, 53, sold his share of Norilsk Nickel in 2008, and has since held stakes in the Brooklyn Nets basketball team and various Russian companies. Some have called him Russia's most eligible bachelor.