ATHENS- Greek Prime Minister Alexis Tsipras will inaugurate the start of construction for the TransAdriatic Pipeline (TAP) in Thessaloniki, Northern Greece on Tuesday. Official representatives of the European Union and U.S. State Department as well as high ranking officials from Greece, Turkey, Albania, Italy and Bulgaria will attend the ceremony. TAP will transport Azerbaijani gas from Shah Deniz-2, extracted in the Azeri sector of the Caspian, to western Europe through Greece and Albania. It is part of the Southern Gas Corridor, one of the most complex gas value chains ever developed stretching over 2,174 miles. The first delivery of Azerbaijani gas is scheduled for early 2020.

The $45 billion project represents the biggest foreign investment that has ever taken place in Greece. The shareholders of the project are: Socar (20 percent), BP (20 percent), Snam (20 percent), Fluxys (19 percent), Enagas (16 percent) and Axpo (5 percent).

This project opens broad opportunities for transportation of Azerbaijani gas to such European markets as Italy, Germany, Great Britain, Switzerland and Austria. It also will help Europe diversify its sources of natural gas. Currently Russia is the major gas supplier for the continent.

At the same time, construction of the pipeline will help the anemic economies of Albania and Greece. It is expected that construction of the pipeline will employ 150 Greek companies as contractors, subcontractors or track support, and about 8,000 workers. On Monday, Greek Minister of Environment and Energy Panos Skourletis told the Athens News Agency, "We are entering into a new phase for the economy. The TAP project will offer a strong boost to move forward." TAP's initial capacity of 10 billion cubic meters (bcm) of gas per year is equivalent to the energy consumption of approximately seven million households in Europe. In future, the addition of two extra compressor stations could double throughput to more than 20 bcm as additional energy supplies come on stream in the wider Caspian region.



Russia is trying to bolster pipeline links with the continent through southern Europe. Gazprom tried and failed to gain strategic entry through Bulgaria and Turkey. Recently it announced new plans with Italian utility Edison and Greece's DEPA to supply natural gas along the seabed of the Black Sea into Greece and Italy, from where it could be sold in Europe. The so-called Interconnector Turkey Greece Italy (ITGI) Poseidon pipeline scheme — unable to get off the ground for years — was shelved in 2012 after it lost out to TAP. Gazprom is now trying to get this project revived. It would consist of an offshore pipeline that will connect the Greek and Italian natural gas transportation systems. The capacity of the pipeline would be 8 billion cubic meters of natural gas a year.

It is expected that during his visit to Athens on May 28 Russian President Vladimir Putin will seek to gain support for the Poseidon pipeline. Follow CNBC International on Twitter and Facebook.

—By Nasos Koukakis, special to CNBC.com