Turkmenistan has won support from its Caspian neighbours to lay a pipeline under the sea and become a major gas supplier to Europe, a senior official said, boosting plans for the EU-backed Nabucco project.

Turkmenistan, which according to BP data, holds the world's fourth-largest natural gas reserves, will have up to 40 billion cubic metres (bcm) of gas spare to supply to Europe, said Baymyrad Hojamuhamedov, deputy chairman of Turkmenistan's cabinet of ministers. He did not specify when this gas would be available.

'Taking into account domestic demand in the west of the country and supplies from there to Iran, we will have 40 bcm of gas free every year, so European countries need not worry,' Hojamuhamedov said.

Turkmenistan, Central Asia's largest natural gas producer, is seeking to diversify exports from its traditional market, Russia, and has already boosted supplies to China and Iran.

It could potentially become a major supplier of gas to the European Union-backed Nabucco project to supply the fuel to European markets.

Nabucco, intended to deliver gas from the Caspian region to Europe, is expected to cost 7.9bn euros ($11 billion) and is seen coming on line with about 15 bcm of gas by the end of 2014.

'Europe is the world's biggest spender on energy imports. Turkmenistan is ideally placed to catch a piece of the action,' said Wolfgang Peters, head of supplies for Caspian, Central Asia and Russia for RWE Supply & Trading.

'We offer a major, attractive and growing energy market with more than half a billion consumers,' said Norbert Jousten, ambassador and head of the delegation of the European Union to Kazakhstan.

Hojamuhamedov said Turkmenistan's president, Kurbanguly Berdymukhamedov, had proposed to a regional summit in Baku that any two of the five countries on the Caspian should be able to agree on laying a pipeline under the sea.

He said 'the majority' of the Caspian countries had agreed to this proposal.