Bilateral effort toward the development of the so-called Southern Corridor of energy transit networks is a sign of close ties to Turkey, a U.S. official said.Turkey aims to position itself as a regional transit hub for oil and natural gas, already hosting a section of the Baku-Tbilisi-Ceyhan oil pipeline, one of the world\'s longest.Azerbaijan, meanwhile, is at the center of a regional energy race spurred by 2009 disputes between Russia and Ukraine, which hosts 80 percent of the Russian natural gas sent to European consumers.Natural gas from Azerbaijan is viewed by Europe as a supply source for its Nabucco natural gas pipeline, a project included in the Southern Corridor of transit networks meant to break Russia\'s grip on the European energy sector.U.S. Ambassador to Turkey Francis Ricciardone said in written statements to the U.S. Senate Foreign Relations Committee during a confirmation hearing that both countries \"are working together to bring Caspian gas to European markets for the first time through a new route called the Southern Corridor.\"Turkey played host in June to a signing ceremony for project support agreements between the five transit countries and the Nabucco pipeline consortium.Ricciardone said the Southern Corridor \"would provide commercial benefit for the countries of the Caucasus and Central Asia and also create a long-term partnership based on mutual interests with Europe.\"Ricciardone took his post as Turkish envoy through a December recess appointment.