ST PETERSBURG, Russia Sat May 24, 2014 11:05am

Russia's President Vladimir Putin said on Saturday a route to supply gas toChina via western Siberia may be implemented faster than the eastern route, through which Moscow has agreed to ship the fuel to its Asian neighbor.

Moscow and Beijing clinched a $400 billion gas deal this week after years of talks, which will help Russia to diversify gas supplies away from Europe, its main export market.

"The second project, if Chinese partners are positive towards it, may be implemented even faster than the eastern one," Putin said on Saturday.

State-run Gazprom (GAZP.MM) has yet to build a pipeline to carry 38 billion cubic meters of gas annually to China from 2018 through East Siberia. Russia and China have agreed a $25 billion prepayment under a supply deal, Alexander Medvedev, the head of Gazprom's exporting arm, said on Friday.

Gazprom had planned to supply a further 30 billion cubic meters of gas per year to China through the western route. Putin said on Saturday the possible amount of gas for this route has yet to be decided.