The plant, which is expected to open by 2021, will help increase its manufacturing capacity by up to 450,000 tons a year.

The expansion is part of Chief Executive Officer Darren Woods' plans to spend $50 billion in the United States over the next five years.

Earlier this month, the world's largest publicly traded oil producer set a goal to double annual earnings by 2025 through heavier investments.

The company has been under pressure from investors, some of whom fear that the company's best days may be behind it.

A final decision on investment for Tuesday's plans, estimated at several hundred million dollars, is expected later this year, Exxon said.

"Abundant supplies of domestically produced oil and natural gas have reduced energy costs and created new sources of feedstock for U.S. chemical manufacturing," ExxonMobil Chemical Co President John Verity said.

"Most of our planned investment in the Gulf Coast region is focused on supplying emerging markets like Asia."

The project will create more than 600 jobs during peak construction and about 60 permanent jobs when production begins, the company said.

Shares of the company were slightly up at $74.42 on Tuesday morning on the New York Stock Exchange.

(Reporting by Nivedita Bhattacharjee; editing by Patrick Graham, Anil D'Silva and Arun Koyyur)

By Nivedita Bhattacharjee