Russia said on Tuesday it was reviewing three options for the South Stream gas pipeline project since the go-ahead from Turkey for the underwater pipeline is still pending.

Speaking at a press conference in Slovenia where Russian gas giant Gazprom signed a $1 billion South Stream joint venture agreement, Prime Minister Vladimir Putin said he saw no threat to the project from Turkey.

"But we are ready for any scenario," he said, adding that Russia would in the next several months present Turkey with additional documentation on the ecological impact from the pipeline and other materials.

Russia plans to launch the $21.5 billion pipeline, which will transport up to 63 billion m3 of gas to central and southern Europe, in 2015. The underwater portion of the pipeline will go through Turkey's territorial waters.

Turkey, also a major player in the rival, European Union-sponsored $10.8 billion Nabucco project to pipe gas from Turkmenistan to Europe, has been in discussions with Russia over prices on gas it buys for domestic consumption.

Putin said Russia may liquefy gas at a new plant on the Black Sea coast and send it to Bulgaria. He said Russia could also liquefy gas at the projected plant in Arctic Yamal peninsula, controlled by Gazprom's rival Novatek.

Right Way To Go
The proposed alternatives will significantly change the South Stream project, where Germany's Wintershall, a unit of BASF, Italy's Eni and France's EDF are involved.

"We are hoping that the project will be implemented in its initial form," Gazprom CEO Alexei Miller told reporters, adding that the deal with Wintershall signed on March 21 may influence Turkey's decision.

"I am sure that the goals we are pursuing with regard to the underwater section will be achieved quicker after BASF entered the project," Miller said, citing a joint experience in obtaining permissions for the Baltic Sea gas pipeline.

Russia earlier said another threat to the project came from the new EU energy legislation which imposes limits on the ownership of pipeline infrastructure by gas suppliers and calls for the "unbundling" of over-concentrated ownership.

On Tuesday Energy Minister Sergei Shmatko said Russia had proposed to the European Union to exempt transborder pipelines from the new rules under which Russia could be forced to sell off parts of its pipeline network in the EU.

Putin said Russia and the EU were "in the process of constructive talks" while Slovenian Economy Minister Darja Radic said Russia should seek an exemption from the new rules dubbed as "the Third Energy Package."

"The Third Energy Package enables exemptions for certain projects and I think that the right way to go would be to try to gain an exemption for the new gas pipelines in Europe," Radic told reporters.