Rockhill Holding Company has agreed to acquire RTW Inc. for about $68 million in cash.

Rockhill sells specialty property-casualty coverage through its Rockhill Insurance Company and Plaza Insurance Company subsidiaries.

RTW, Minneapolis, sells return-to-work services, absence-management services and related services to disability insurers, workers’ compensation insurers and other insurers.

RTW will operate as a separate subsidiary after the deal is completed, Rockhill says.

The boards of both companies have approved the deal, and the companies hope to complete it by Dec. 31.

“We believe we are putting RTW and its customers in very good hands,” RTW Chairman John Goodwyne says in a statement about the deal. “We are pleased that Rockhill will pay RTW shareholders a price per share that we believe is good value and provide immediate liquidity in a very thinly traded stock. The price of $12.45 represents a premium of 54% percent over the Nasdaq market price on Sept. 20, 2007, and is at a price higher than RTW stock has traded for at least the past 5 years. It has been a difficult market for small public companies, and we believe this transaction provides significant immediate shareholder value while enabling RTW to continue to provide quality service to its customers.”