Westlake Chemical Corp. said Wednesday that it boosted its offer to buy Georgia Gulf Corp. to about $1.2 billion in cash, but that the revised offer was rejected by the Georgia Gulf board.

Westlake's most recent hostile takeover offer of $35 per share represents a 17 percent increase over its previous bid of $30 per share. It's also nearly equal to Georgia Gulf's Tuesday closing share price of $35.05.

In morning trading, Georgia Gulf shares fell $1.59, or 4.4 percent, to $33.45, while Westlake Chemical lost 84 cents, or 1.4 percent, to $57.61.

Houston-based Westlake also said in a letter to Georgia Gulf shareholders that it's willing to pay part of the purchase price in shares of its stock.

The letter also states that Westlake has decided against nominating directors to Georgia Gulf's board at the company's annual shareholder meeting, so that the companies can take part in negotiations on a "friendly basis" and reach a mutually beneficial deal.

Atlanta-based Georgia Gulf makes two lines of chemicals, chlorovinyls and aromatics, and manufactures vinyl-based building and home-improvement products.

Westlake, which supplies petrochemicals, polymers and building products, made its first offer of $30 per share in September without announcing it publicly. It went public with the offer in January, after it said Georgia Gulf was unwilling to take part in talks.

Georgia Gulf subsequently adopted a "poison pill" shareholder rights plan that would go into effect if any company or investor acquires a 10 percent stake in the company. That could make a buyout prohibitively expensive.

A spokesman for Georgia Gulf did not immediately return calls for comment.