Gazprom, Russia's natural gas giant, has called for greater transparency in the ownership of a secretive intermediary that will control all gas imports to Ukraine, amid continuing controversy over the two-week-old deal to end the gas pricing dispute between the two countries.

The call from Alexei Miller, Gazprom's chief executive, comes as the state-controlled gas monopoly strives to increase its attractiveness to investors. Foreign investors have been piling into its stock since restrictions on foreigners owning Gazprom's 49 per cent free float were lifted at the end of last year.