BELMONT COUNTY, Ohio — The company weighing whether or not to build a $5.7 billion ethane cracker plant in Belmont County has delayed its final investment decision.

The president of PTT Global Chemical said in a statement late Tuesday that the company will announce its decision for the Ohio project in late 2017, several months later than originally proposed. Company officials say they want more time to study the economic and engineering feasibility of the project with contractors and consultants, which “PTT considers…to be critical to the success of the project.”

Despite the delay, the company said it has made “significant progress” in site development and other areas, and has enjoyed the full support of local and state officials during the process.

CEO Toasaporn Boonyapipat wrote, “For some in the Belmont County community, especially the project area residents, we recognize this delay may cause further uncertainty and inconvenience.” He added, “We hope that the strong support we have received to date will continue.”

PTT Global Chemical has already invested $100 million in preliminary site work, while JobsOhio has contributed $14 million to clearing the development site in Dilles Bottom, along the Ohio River.

The company has also already secured three environmental permits related to site preparation, as well as “commercial arrangements” with feedstock and utility suppliers for the proposed plant.

If built, the project would employ thousands of construction workers and hundreds of full-time workers when the plant becomes operational.