CHATTANOOGA, Tenn. – Pennsylvania’s insurance commissioner signed on to a settlement in a multistate investigation of claims handling by UnumProvident Corp., the nation’s largest disability insurer.

Pennsylvania Insurance Commissioner Diane Koken said Tuesday she signed the regulatory agreement that requires the Chattanooga-based insurer to change claim practices and reconsider more than 200,000 previously denied claims.

UnumProvident also will pay a $15 million fine, company executives said Thursday.

The company, which insures more than 25 million people and has about a quarter of the market, estimates the settlement will cost it $127 million in restitution to policyholders and in enacting required changes.

About 10,000 Pennsylvania claims will be reassessed, Koken said.

Last week, insurance regulators in Tennessee, Maine and Massachusetts released a report on the investigation and endorsed the agreement, which company executives said would become valid when approved by two-thirds of the states.

The multistate agreement was negotiated under the auspices of the National Association of Insurance Commissioners.