UPDATE 1-Eaton to buy Tuthill's coupling unit

NEW YORK Dec 16 (Reuters) - Diversified industrial company Eaton Corp (ETN.N) will buy the coupling division of Tuthill Corp for an unspecified sum, expanding its range of hydraulics products, Eaton said on Thursday.

The Tuthill Couplings Group, with sales of $35 million in the 12 months to November, makes hydraulic and pneumatic connectors used in industrial, construction, mining and other applications.

Eaton has been active on the acquisition front in recent months. Its September agreement to buy electrical systems maker CopperLogic was the third deal in a span of three months. The CopperLogic acquisition closed in October.

The Cleveland-based company is also said to be in the race for BAE Systems Plc's (BAES.L) Platform Solutions unit, people familiar with the auction told Reuters this month.[ID:nN03143723] (Reporting by Nick Zieminski, editing by Gerald E. McCormick)