DUBAI—Saudi Aramco aims to buy a controlling stake in petrochemical maker Saudi Basic Industries Corp. (SABIC), possibly taking the entire 70% stake owned by Saudi Arabia’s sovereign wealth fund, two sources familiar with the matter told Reuters.

Late last week Aramco confirmed a Reuters report that it was working on a possible purchase of a “strategic stake” in SABIC from the Public Investment Fund, the kingdom’s top sovereign wealth fund.

Aramco’s initial thinking is to buy the full stake owned by the Public Investment Fund (PIF), but if that fails to materialize Aramco could end up with a stake in SABIC of more than 50%, making it a majority owner, the sources said.

No final decision has been made on the size of the stake as the discussions are still at a very early stage, they added.

Aramco declined to comment. The PIF did not respond to a Reuters request for comment.

Riyadh-listed SABIC, the world’s fourth-biggest petrochemicals firm, has a market capitalization of $103 billion.

The potential acquisition would affect the time frame of Aramco’s planned initial public offering set for later this year, the state oil giant’s CEO, Amin Nasser, said in a TV interview on July 20.

Aramco plans to boost investments in refining and petrochemicals to secure new markets and sees growth in chemicals as central to its downstream strategy to cut the risk of an oil demand slowdown.

Aramco plans to raise its refining capacity to between 8 million and 10 million barrels per day, from around 5 million bbl/d now, and double its petrochemicals production by 2030.

Aramco, the world’s largest oil producer, pumps around 10 million bbl/d of crude oil.