COTTONWOOD, Ariz.- United Rentals has reached a definitive agreement with RDO Equipment Co. to acquire its rental division, RDO Rental Co. Terms of the t ransaction were not disclosed.

Based here, RDO Rental, No. 45 on the RER 100, has 12 locations in Arizona, California and Nevada. Its revenues for the 12 months ended Oct. 31 were about $27.6 million. The transaction is subject to customary conditions.

RDO Equipment, Fargo, N.D., operates the largest network of John Deere construction and agricultural equipment dealerships and Volvo truck centers in North America, and had revenues of $673 million for the 12 months ended Oct. 31. Company officials said the sale of its rental division would strengthen its balance sheet and allow for the expansion of business units in which the company has strategic advantage.

Bill Hutton, former president of RDO Rentals, told RER he has agreed to stay on for a 90-day transition period beginning Feb. 1, but potential involvement after that had yet to be discussed.

Greenwich, Conn.-based United Rentals is the largest rental company in North America with 676 branches in 44 states, six Canadian provinces and Mexico.