OREANDA-NEWS. Westlake Chemical raised its bid to acquire rival Axiall to $3.1bn in cash, stock and debt, up 17pc from its original proposal.

Axiall's board rejected the offer but said it was not opposed to a deal if Westlake accurately valued it for Axiall shareholders.

"... the value you currently propose simply ignores the high quality of our assets, the significant growth potential of our business and the powerful synergies available in a combination," Axiall chief executive Timothy Mann wrote in a letter to Westlake.

Axiall said Westlake undervalued the value of the synergies between the two companies, estimating combined cost reductions of $270mn, not the $60mn estimated by Westlake.

Houston-based Westlake called Axiall's estimate "unrealistic" in a letter urging shareholders to vote to replace Axiall's board. It intends to nominate its own candidates to Axiall's board.

Axiall has not yet scheduled the date of its 2016 annual shareholders' meeting.

Axiall manufactures chlor-alkali and chlorovinyls. Westlake manufactures olefins and vinyls.