THE HAGUE, Netherlands — Dutch industrial paints and chemicals company AkzoNobel today rejected a third unsolicited takeover bid from American rival PPG Industries, worth $28.8 billion, saying it was not in the interests of shareholders.

“The PPG proposal undervalues AkzoNobel, contains significant risks and uncertainties, makes no substantive commitments to stakeholders and demonstrates a lack of cultural understanding,” AkzoNobel CEO Ton Buchner said in a statement.

AkzoNobel said that its own plan, announced last month, to spin off its Specialty Chemicals unit within 12 months to boost growth “offers a superior route to growth and long-term value creation and is in the best interests of shareholders and all other stakeholders.”

AkzoNobel announced the shake-up after rejecting two earlier PPG bids, saying they undervalued the company.

Last month, PPG Industries upped the ante again with a third bid for AkzoNobel; a cash-and-stock deal valued at about $28.8 billion.

AkzoNobel said it rejected the latest offer after “considerable in-depth analysis” including talks with PPG’s CEO, Michael McGarry.

PPG said in a statement posted on its website that it was disappointed by the latest rejection.