HOUSTON (Reuters) - Saudi Aramco IPO-ARMO.SE took the first steps toward expanding the largest U.S. refinery on Saturday, which is operated by its subsidiary Motiva Enterprises.

FILE PHOTO - Logo of Saudi Aramco is seen at the 20th Middle East Oil & Gas Show and Conference (MOES 2017) in Manama, Bahrain, March 7, 2017. REUTERS/Hamad I Mohammed/File Photo

Aramco’s Chief Executive Amin Nasser signed agreements with Honeywell UOP, (HON.N) and Technip FMC (FTI.N) to study petrochemical production technology for use in a multi-billion-dollar chemical plant the company is considering building at the Port Arthur refinery.

“These agreements signal our plans for expansion into petrochemicals,” said Motiva’s Chief Executive Brian Coffman.

Coffman also said Motiva is evaluating boosting the 603,000 barrel-per-day (bpd) refinery’s capacity to 1 million or 1.5 million bpd, which would make it the largest in the world.

Saudi Arabia’s Crown Prince Mohammed bin Salman, who is finishing a two-week visit to the United States, Saudi Energy Minister Khalid al-Falih and U.S. Energy Secretary Rick Perry were present at the signing.

FILE PHOTO - Chief Executive Officer of ARAMCO, Amin Nasser speaks during an interview with REUTERS in Dhahran, Saudi Arabia, December 13, 2017. REUTERS/Hamad I Mohammed

The aromatics unit for which Honeywell UOP’s technology is being considered would convert benzene and paraxylene, byproducts of gasoline production, into 2 million tons annually of feedstocks for chemicals and plastics.

The Technip FMC technology would produce 2 million tons a year of ethylene, which is used to make plastics, Motiva said.

The final investment decision on the Port Arthur petrochemical plant is not expected until 2019, Motiva said in a statement.

Coffman did not provide a timeline for the possible expansion of the Port Arthur refinery’s crude oil processing

Read more from our friends at Reuters: