MOSCOW, March 13 (RIA Novosti) - The project to build a gas pipeline along the Caspian Sea coast is more feasible than the rival Western-backed Nabucco trans-Caspian pipe bypassing Russia, a Russian senior diplomat said on Thursday.

Russia, Turkmenistan and Kazakhstan signed a deal in December to supply the Asian states' Caspian gas via Russia, dealing a blow to the Nabucco pipeline. Moscow also reached deals with Bulgaria and Serbia earlier this year on the South Stream pipeline to pump Central Asian gas to Europe.

"From the economic viewpoint, the Caspian gas pipeline project is more viable than other projects. Under this project, it will be possible to expand the capacity of the existing pipeline system that is unable to cope with required gas volumes," First Deputy Foreign Minister Andrei Denisov told Vremya Novostei newspaper.

The $6 billion Nabucco pipeline, backed by the EU and the U.S. is expected to link energy-rich Central Asia to Europe through Turkey, Bulgaria, Romania, Hungary and Austria. Its construction could begin in 2010.