Activist investor Trian wants PPG Industries to oust its CEO Michael McGarry and replace him with former chairman and CEO Charles Bunch, while also suggesting the US paintmaker should split into two.

Nelson Peltz’s New York-based investment company, which revealed a 2.9% stake in PPG earlier this month, blames McGarry for its underperformance during the past three years.

In a presentation at an investor conference on Oct. 25, Trian’s chief investment officer Ed Garden said now is the right time to bring back Bunch, who has apparently indicated his willingness to return to his former role. Bunch led PPG from 2005 to 2015.

Trian said PPG has suffered a series of operational and strategic mishaps under McGarry. These include three consecutive years of profit warnings, including this month when the company said third- and fourth-quarter earnings would be lower than expected; accounting irregularities; the loss of key customer home improvement retailer Lowe’s; and the ‘ill-advised’ attempted hostile takeover of Dutch coatings group AkzoNobel.

After replacing McGarry with Bunch, Trian wants PPG to consider splitting into two separate, publicly traded companies, with one focused on global architectural coatings and the other focused on manufacturers and industrial business. Trian said the separated units would be better positioned for more strategic acquisitions in the future.

Responding to Garden’s comments, PPG said its board of directors unanimously supports McGarry as chairman and CEO although it is open to listening to Trian on other topics. “The management team remains actively focused on delivery strong results, including top-quartile operating margins, in a challenging macro-environment for the industry and continuing to grow its business through innovative technology and disciplined acquisitions,” it said in a statement.

In a note to clients by Christopher Parkinson, an analyst with Credit Suisse quoted by the Bloomberg news agency, the analyst said criticism should not be solely directed at McGarry. While PPG shareholders are “naturally frustrated,” the sector as a whole has experienced an unprecedented period of raw materials inflation, foreign exchange volatility and a fall-off in key markets during McGarry’s tenure, Parkinson said.