The agreement was signed by representatives of the four nations and the TAPI Pipeline Project Company in Istanbul, reports Dawn.
They had already registered the company in November 2014 in which Afghanistan, Pakistan and India would have five percent shareholding each and the remaining 85 percent stake would be held by Turkmenistan.
"We have initialed an investment agreement in Istanbul and the final deal will be signed soon," The Express Tribune quoted Interstate Gas Systems Managing Director Mobin Saulat as saying.
Pakistan would contribute five percent of the financing for different activities of the project, he said.
The TAPI pipeline is expected to bring peace and stability in the region in the wake of regional cooperation as Afghanistan, Pakistan and India will be depending on each other. This project will also connect South Asia and Central Asia. (ANI)