"PPG as a matter of policy does not comment on market rumors or speculation," Bryan Iams, vice president for corporate and government affairs at PPG Industries, told CNBC in an email.
Shares of Pennsylvania-based PPG Industries spiked more than 12 percent in afternoon trade, but later pared those gains. The stock ended the day 6 percent higher and was the second biggest advancer in the S&P 500 Wednesday.
Akzo Nobel, which is based in the Netherlands, saw its over-the-counter U.S.-traded shares jump more than 10 percent in afternoon trade.
"We never comment on market rumors," Akzo Nobel spokeswoman Mirjam Veenhof told CNBC over the phone.
Shares of competitor Axalta Coating Systems traded about 3 percent higher after the Bloomberg report.
—CNBC's Jim Forkin and Evelyn Cheng contributed to this report