The Russian Kremlin has expanded its role in radio and television broadcasting with the purchase of mining tycoon Vladmir Potanin's Profmedia by the media arm of the state-controlled Gazprom, the former Soviet gas ministry.

Through Tuesday's deal, Gazprom, now Russia's largest company by revenue, will add TV and radio stations, cinemas, and film production and distribution assets to a business that it has established around commercial television channel NTV, Reuters reports.

Gazprom Media and Interros, Potanin's investment company, said the deal would be finished by the start of 2014, subject to regulatory approvals.

Gazprom Media's board of directors is chaired by Gazprom's chief executive, Alexei Miller, whom President Vladimir Putin hand-picked to run Russia's gas export monopoly in his first term. Gazprom owns a 35 percent direct stake in Gazprombank, which in turn owns 100 percent of Gazprom Media.

Gazprom bought NTV in 2000 from Vladimir Gusinsky, a media tycoon who went into exile after a crackdown on coverage critical of the Kremlin after Putin became president.