Gerhard Schröder, the former chancellor of Germany, has been nominated to join the supervisory board of Russian state-owned gas company Gazprom, the company announced on Friday. Schröder, who led Germany from 1998 to 2005, is a Social Democrat and friend of Russian President Vladimir Putin. His links to Russia are often the source of controversy, including within his own party, which leads the new coalition government. His appointment to Gazprom’s supervisory board is to be sealed at the annual general meeting on June 30. Schröder will replace Timur Kulibayev, a son-in-law of former Kazakh pre…