Saudi Aramco, the world's biggest oil company, and its partner Abu Dabhi National Oil Co (ADNOC) will have marketing rights for half of the fuel produced by the planned $44-billion refinery in Maharashtra but cannot export them without first offering to local companies.

Aramco and ADNOC will together hold 50 percent stake in the 60 million tonne per annum (MTPA) refinery and adjacent 18 MTPA petrochemical complex planned to be built at Ratnagiri district of Maharashtra by 2025.

"Marketing rights will be in proportion to the shareholding in the refinery. So they (Saudi Aramco and ADNOC) will get marketing rights over 50 percent of the produce," said Sanjiv Singh, Chairman of Indian Oil Corp (IOC), which is leading the domestic refiners in the project.

The two firms can sell fuels like petrol and diesel in the domestic market. "They are free to market their share but they cannot export without first offering it to us," he said.

This clause has been inserted to meet domestic demand first. "We want to protect our market and meet domestic requirement first. So we will have first right of refusal and only when it is waived can they export fuel," he said.

IOC will hold 25 percent stake in the project while Bharat Petroleum Corp Ltd (BPCL) and Hindustan Petroleum Corp Ltd (HPCL) are to split the remaining equally among themselves.

ADNOC had in June signed an initial pact to join the project by agreeing to take a part of the 50 percent stake that Saudi Arabia's national oil company had picked up in the project earlier this year.

Singh said how the 50 percent stake would be split between Saudi Aramco and ADNOC is not known.

Aramco and ADNOC will supply half of the crude oil required for processing at the refinery. Like other major producers, the two are looking to lock in customers in the world's third-largest oil consumer through the investment. Kuwait too is looking to invest in projects in return for getting an assured offtake of their crude oil.

Last year, Saudi Arabia invested in refinery projects in Indonesia and Malaysia that came with long-term crude oil supply deals.

Singh said the state government was "extremely supportive" of the project and is helping in land acquisition, which is facing local resistance.

The project will need 15,000 acres of land, he said adding the companies are engaged with locals to address their issues.

The first production will start in 2022. Full capacity will be reached by 2025.

India has a refining capacity of 232.066 MT, which exceeded the demand of 194.2 MN in 2016-17.

According to the International Energy Agency (IEA), this demand is expected to reach 458 MT by 2040. IOC has 11 refineries with a total capacity of 81.2 MT, while BPCL has four refineries with a capacity of 33.4 MT. HPCL has three refineries with a total capacity of 24.8 MT.