MUNICH, July 15 (RIA Novosti) -Nabucco is not a serious rival to Russia's Nord Stream and South Stream gas pipeline projects, First Deputy Prime Minister Viktor Zubkov said on Wednesday.

An intergovernmental agreement on the transit of Caspian gas to Europe as part of the Western-backed Nabucco gas pipeline project was signed on Monday in Turkey at a ceremony attended by European Commission President Jose Manuel Barroso and officials from about 20 countries.

The project, estimated at $7.9 billion, is designed to pump Central Asian gas via Turkey to Austria and Germany through Bulgaria, Romania and Hungary. The pipeline, intended to bypass Russia, is planned to go on stream in 2014.

"We don't believe that Nabucco is a serious rival to our projects, which you know well - the Nord Stream and South Stream," Zubkov said, adding that experts did not believe there was sufficient gas to fill the Nabucco pipe.

Among the potential gas suppliers for the pipeline are Azerbaijan, Uzbekistan, Turkmenistan, Iran and Iraq.

The South Stream project is designed to annually pump 31 billion cubic meters of Central Asian and Russian gas to the Balkans and onto other European countries, with the pipeline's capacity expected to be eventually increased to 63 bcm annually.

The 6 billion-euro Nord Stream pipeline being built jointly by Russia and Germany under the Baltic Sea is planned to eventually pump 55 bcm of gas per year to Western Europe, bypassing traditional transit nations.

Europe has expressed concerns about being dependent on Russia, which supplies a quarter of its gas needs. Calls for diversified supplies intensified following a recent bitter price dispute between Russia and Ukraine in early 2009, when Moscow cut off gas to Ukraine, affecting consumers across Europe.

Moscow has argued, however, that South Stream and Nord Stream would cut EU dependence on transit states like Ukraine and improve European energy security.