The transaction stemmed from an unsolicited inquiry made by a private equity firm a month ago, said Chief Executive Officer Peter Huntsman, son of founder Jon Huntsman Sr. A board committee hired Merrill Lynch & Co. to contact previous suitors, including Access, and Huntsman management gave a presentation to the potential buyers about two weeks ago, he said.

"We had to look first and foremost at what is good for our shareholders," Peter Huntsman said in the interview from New York. "There was a real process. We worked with multiple companies."

Huntsman is the world's biggest maker of epoxy adhesives, and the second-largest producer of methylene diphenyl diisocyanate, or MDI, used in polyurethane products such as foam insulation, coatings and adhesives. Huntsman also makes textile dyes and titanium dioxide, a white pigment.

The boards of Huntsman and Basell have approved the transaction. Closing is expected in the fourth quarter, pending regulatory approvals.

Huntsman last year considered selling the company, saying the share price didn't accurately reflect its value. Talks with potential buyers were abandoned because Huntsman deemed the offers too low. The company then began selling commodity businesses.