Oettinger, speaking Thursday at the Southeastern Europe Gas Forum in Brussels hosted by the developers of the project, said the effort is in line with EU's goals of lessening the region's dependence on Russia for natural gas supplies.
"Trans-Adriatic Pipeline is a very promising project," the EU energy chief said. "It is a cost effective, very straightforward solution to gas transportation."
The EU, he said, is working hard on upgrading the lack of interconnection of gas infrastructure in southeastern Europe, which makes its vulnerable to interruptions in Russian supplies.
The Trans-Adriatic Pipeline, or TAP, would also be a step in the that direction, as well.
"This is in particular needed for gas in a vulnerable infrastructure such as in Southeast Europe," he said. "I do not need to remind you of the dramatic effects the dispute between Ukraine and Russia in January 2009 had in that region.
"But diversified gas supplies also will make gas a more attractive source of energy, shifting away from old and dirty installations for electricity generation or domestic heating."
EGL of Switzerland, Norway's Statoil and E.ON Ruhrgas of Germany are proposing the construction of the Trans-Adriatic Pipeline, which would run 500 miles from the Greece-Turkey border, through Albania and under the Adriatic Sea to Italy and then on to Western Europe.
The pipeline would carry about 10 billion cubic meters of natural gas per year.
"Electricity remains expensive in Italy, hence commercially speaking TAP has a promising business plan," Oettinger said.
But for the TAP pipeline to work, he added, it needs to have gas supplies from the Shah Deniz II field in Azerbaijan reliably delivered through Turkey to the border with Greece.
TAP's backers last month sent third-party access exemption applications to the host countries that would let the consortium enter into a ship-or-pay gas transportation agreement with shippers working in Azerbaijan.
Baku is expected to soon choose from a number of gas transit networks outlined in the so-called Southern Corridor, which includes TAP and the Nabucco project.
Oettinger said pipeline projects within the EU, such as TAP and the Interconnector Turkey-Greece, need to be hooked up with a stable supplier through non-EU Turkey for the Europe's public policy aims at diversifying energy sources to be satisfied.
"The scope for cooperation is there and so are the gas reserves in the Caspian region," he said. "Indeed, TAP, if married to a stable, legally defined transit agreement in Turkey, that satisfies the criteria of the January joint Commission-Azerbaijan declaration, would be an even more valuable project."
This could be done through small steps or through a "big bang," but, he said, what really matters "is that it is (cost-effective) and that gas transmission can be expanded to meet all reasonable new offers of gas."
At the same conference, TAP Managing Director Kjetil Tungland told delegates that getting natural gas from Azerbaijan was vital for regional energy security.
"TAP is the only pipeline which can fulfill this vision in a cost-effective, technically reliable and commercial way," he said.
Connecting southeastern Europe to Caspian gas supplies "will diversify the region's energy sources and contribute to the creation of a truly pan European gas market," he added.