MOSCOW (Reuters) - Sanctions imposed by the United States on Russia's third largest lender Gazprombank, which handles the energy trade, are behind the rouble's free fall in recent days, a top executive from VTB, Russia's second largest bank, said on Wednesday.

"My assumption is that the sanctions against Gazprombank have had a significant impact, as it has ceased to be a channel for delivering foreign currency to the Moscow Exchange," Dmitry Pyanov told reporters.

Pyanov added that stabilisation of the forex market within the next few days should be the focus of the central bank's attention.