The company will acquire a 15% stake in the project.
Norwegian oil and gas company Statoil and Switzerland-based Elektrizitäts-Gesellschaft Laufenburg (EGL) are the existing partners of the consortium, each holding a 42.5% share in the natural gas pipeline project.
The TAP project connects existing and planned natural gas transport grids in south-east Europe with gas systems in western Europe via Italy, the Adriatic Sea, Albania and Greece.
EGL CEO Hans Schulz said: “It has always been our intention to attract additional strong partners able to add value to this project.”
Rune Bjornson, executive vice president of natural gas at Statoil, said that the move will further strengthen the TAP project and its ability to compete for gas volumes to be transported from the Caspian region to Europe.