GAIL India, the country's largest gas marketing and distribution company, plans to acquire 10% stake in 'ONGC Petro Additions' (OPaL) petrochemical complex project coming up in Dahej. The investment cost of the deal has been estimated at Rs1,500-2,000 crore. Besides GAIL, another Public Sector Unit Petronet LNG (PLL) is also aiming to pick up 5 % stake in the project. ONGC holds 26 % stake in OPaL while government-run Gujarat State Petroleum Corporation (GSPC) holds 5 % equity. The petrochemical complex will be located in the Dahej SEZ and will come up on 500 hectares, with an extraction unit near it on 55 hectares.