CHATTANOOGA, Tenn. (AP) – Insurance officials in Maine and Massachusetts have joined with Tennessee insurance regulators in an investigation of claims handling by UnumProvident Corp., the nation’s largest disability insurer.

The company has major business operations in those three states.

Tom White, UnumProvident’s vice president of corporate relations, said company officials are confident the investigations will validate the insurer’s performance. UnumProvident says it has about 30 percent of nation’s disability insurance business.

The company was fined $1 million in March by Georgia insurance regulators following an investigation of its claims handling. Georgia State Insurance Commissioner John Oxendine said UnumProvident had a corporate mentality of “looking for every technical legal way to avoid paying a claim.”

Eric Cioppa, deputy superintendent of the Maine Bureau of Insurance, said officials in the three states are cooperating. Chris Goetcheus, a spokesman for the Massachusetts Division of Insurance, said that agency started its review of UnumProvident early this year.

“It’s a work in progress,” he said.

Paula Wade, a spokeswoman for the Tennessee Department of Commerce and Insurance, said Tennessee is looking at the company “in the context of what other folks have found. We’re looking at the potential patterns of conduct.”

She said the states plan a unified report “fairly soon.”

Hundreds of lawsuits have been filed by policyholders who contend the company routinely denies claims and requires its medical employees to support the denials.

UnumProvident also has been hit with lawsuits from shareholders who claim it made misleading statements about its finances.

The company is searching for a successor to chief executive J. Harold Chandler, who was ousted in March. White said that search process was continuing.

UnumProvident and its subsidiaries have about 13,000 employees, including about 3,600 in Portland, Maine; about 3,000 in Chattanooga and about 800 in Worcester, Mass.