"Our board has carefully considered Mr. Icahn's revised proposal and concluded that it is inadequate and unlikely to be completed," Clorox's lead director Gary Michael said a statement.
Last Wednesday, Icahn raised his bid for the Oakland, California-based company from $76.50 to $80 per share, increasing his implied valuation of Clorox from $10.2 to $10.7 billion.
Icahn, who is famed for his aggressive buyout tactics, already owns 9.4 percent of Clorox.
He made his initial offer for Clorox in mid-July in hopes of starting a bidding war for the company and attracting even more lucrative offers from elsewhere.
Clorox makes a variety of consumer products sold under different brand names around the world but is best known for its household bleach and cleaning products. It had over $5.5 billion in sales last year.
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