NEW YORK ( The Deal) -- An organization affiliated with the Pritzker family said Monday it would acquire steel mill services company TMS International ( TMS) for about $1 billion in cash and assumed debt.Terms of the deal call for merchant bank Pritzker Organization to pay $17.50 per share for TMS, a premium of about 12% to the Pittsburgh-based target's Friday close. The deal values TMS' equity at about $687 million, and also includes more than $300 million in debt. TMS is a provider of outsourced industrial services to North American steel mills, operating through subsidiaries including Tube City IMS. The company helps steel mills buy and sell scrap metal, providing services at 81 customer sites in 12 countries and via 36 brokerage offices. The target since 2007 has been controlled by Onex, which acquired Tube City from Wellspring Capital Management for $625 million. TMS went public in 2011, raising $145.6 million, but Onex retains a nearly 60% stake in the firm. "We have built a world-class outsourced industrial services company over the past six years during our partnership with Onex," TMS chief executive Raymond Kalouche said in a statement. "With this transaction, we are pleased to be able to maximize stockholder returns while positioning ourselves to continue to deliver exceptional value for our customers and expand our global operations as a privately held company." Though the Pritzkers are best known for their hotel and real estate holdings, the family has a long history of also dabbling in industrial assets, including past ownership of marine intermodal cargo container giant Triton Container International and diversified manufacturer Marmon Holdings, which it sold to Warren Buffett's Omaha-based Berkshire Hathaway ( BRK.B) in 2007. More recently the family in January acquired Intersystems, a manufacturer of specialized material handling equipment for the agriculture industry, for an undisclosed price. Pritzker Organization chairman and CEO Tom Pritzker said in a statement that the family operation is "delighted to have the opportunity ... to participate in and support the growth" of TMS over time. "TMS is a leading provider of mill, procurement and logistics services to the steel industry, with an exceptional management team and a proven track record of delivering value to its customers," Pritzker said. "We look forward to working closely with the TMS management team in a similar fashion to help them build on their impressive track record of success."