National oil firm Saudi Aramco plans to cut its stake in Sadara Chemical Co, a joint venture with US company Dow Chemical, via an initial public offer of shares, Sadara chief executive Ziad al-Labban said.

"Aramco has a stake of 65% in Sadara - they want to become equal with Dow, which has a 35% stake. The 30% I believe will be IPOed by Saudi Aramco," Labban told reporters on the sidelines of a petrochemical industry conference.

He did not give a timeline or other details. Executives first raised the possibility of an IPO for Sadara years ago; a source familiar with the matter told Reuters this year that it would occur after the planned IPO of Aramco itself, which is due to take place in 2018.

As MRC informed before, in June 2016, Saudi Arabian Oil Co. and Saudi Basic Industries Corp. (Sabic) became one step closer to building their first plant to process crude directly into chemicals, cutting out a link in the production chain from hydrocarbons to the finished products that go into plastics and other consumer goods. The state-owned companies signed an agreement to study such a project to be located in Saudi Arabia. A joint venture is possible if the companies decide to move ahead after the study is completed by early 2017, they said. Oil companies normally refine crude into transportation fuels including gasoline and diesel and leave byproducts such as naphtha to be processed separately into chemicals.