New Delhi: Saudi Aramco and a consortium of Indian state refiners have agreed to build a mega refinery and a petrochemical facility on India's west coast for an estimated $44 billion, oil officials present at the signing of an initial agreement said on Wednesday.

Top executives of Saudi Aramco and India's Ratnagiri Refinery & Petrochemicals (RRPL) - a joint venture of Indian Oil, Hindustan Petroleum and Bharat Petroleum - signed a memorandum of understanding to take equal stakes in the project in Maharashtra.

The project includes a 1.2 million-barrel-per-day (bpd) refinery integrated with petrochemical facilities with a total capacity of 18 million tonnes per year, the officials said on the sidelines of the International Energy Forum, a gathering of oil producers and consumers.

The plant will be one of the largest refining and petrochemical complexes in the world, built to meet the fast-growing fuel and petrochemicals demand in India and elsewhere, and providing a steady outlet for Saudi crude oil, they said.

"Large as this project may be, it does not by itself satisfy our desire to invest in India ... We see India as a priority for investments and for our crude supplies," Saudi Arabia energy minister Khalid al-Falih said.

"We're very much interested in retail ... We want to be consumer facing," he said.

"There will be two blocks of investors (in Ratnagiri) that include 50 per cent of Indian companies and the remaining by a block of foreign companies. Later, we can bring in other interested parties as part of the foreign block," said Al-Falih.

Saudi Aramco will supply at least 50 per cent of the crude to be processed at the planned refinery, officials said.

The mega refinery is likely to be completed in seven years and may see Saudi Aramco bringing in other partners such as Abu Dhabi National Oil Company that have shown interest in joining the project. Saudi's petrochemical company SABIC is also keen to invest in a cracker and other facilities in India, he said.

Aramco, like other major producers, wants to tap the rising demand and invest in the world's third-biggest oil consumer. Last year it opened an office in New Delhi.

"Investing in India is a key part of our company's global downstream strategy, and another milestone in our growing relationship with India," said Aramco president and chief executive Amin Nasser.

"Participating in this mega project will allow Saudi Aramco to go beyond our crude oil supplier role to a fully integrated position that may help usher in other areas of collaboration such as refining, marketing and petrochemicals for India's future energy demands."

India outlined plans in February to expand its refining capacity by 77 per cent to 8.8 million bpd by 2030.

Saudi Aramco, the world's biggest oil exporter, is moving to invest in refineries overseas to help lock in demand for its crude, and expand its market share ahead of an maiden offering that is expected later this year or next year.