Backers of a pipeline meant to reduce Europe's dependence on Russian gas clashed today at a high-level energy meeting with supporters of a rival project which would strengthen Moscow's near-monopoly on supplying the continent, according to AP. Backers of the South Stream pipeline, which will transport Russian natural gas under the Black Sea through Bulgaria to other European countries, sought the EU's endorsement. But Europe, which has been increasingly nervous about its reliance on Russia for energy, is supporting a proposed separate pipeline, called Nabucco, which would import Caspian gas and bypass Russia entirely. The meeting, dubbed «Natural Gas for Europe, Security and Partnership,» is being attended by gas suppliers from the Caspian region, Central Asia and the Middle East, and importers from the Balkans and the European Union. However, the summit ran into troubled waters before even starting _ Russian Prime Minister Vladimir Putin unexpectedly bowed out of the meeting, apparently because of differences with Sofia over the South Stream project. At issue is the pipeline's stretch through Bulgaria, which is vital for its whole network. Putin was hoping for a firm endorsement by Bulgaria before the summit, which would have allowed Russia to promote South Stream as the best gas supply option. «Linking an agreement to participation in the summit is unacceptable,» Bulgarian Foreign Minister Ivailo Kalfin said, adding that unresolved questions remained about ownership of the pipeline on Bulgarian soil. Bulgaria, hard hit by a Russia-Ukraine gas dispute in January, said it wants a multilateral dialogue on energy to avert future crises.