The TAP project consortium and Interconnector Greece-Bulgaria signed a memorandum of understanding to consider further development of gas infrastructure in the region.
"We welcome this agreement with ICGB and see it as an opportunity to transport Caspian gas to Bulgaria, thus enhancing diversification of supply and improving security of supply in the country and in the wider South Eastern Europe Region," Landwehr said in a statement.
Landwehr said the agreement calls on both sides to consider a possible pipeline connection point in Greece that would allow natural gas to flow to Bulgaria.
The Greek government ratified a host agreement for TAP in December. The 340-mile section through Greece is the longest for the 540-mile pipeline.
TAP will connect to a pipeline near the Turkish border with Greece and cross through the Adriatic Sea before it heads to European markets from Italy. The project will deliver more than 350 billion cubic feet of natural gas to European markets when it goes online in 2019.
Construction of the pipeline itself is slated for 2015.
Notable deaths of 2014 [PHOTOS]