In April 2017, we entered into an agreement to form a joint venture with Eaton Corporation PLC (Eaton), which closed on July 31, 2017 (the acquisition date). We purchased a 50 percent interest in the new venture named Eaton Cummins Automated Transmission Technologies for $600 million in cash. In addition, each partner contributed $20 million for working capital. The joint venture will design, assemble, sell and support medium-duty and heavy-duty automated transmissions for the commercial vehicle market, including new product launches. The new generation products (Procision and Endurant) were launched in 2016 and 2017, respectively, and are owned by the joint venture. Eaton will continue to manufacture and sell the old generation products to the joint venture which will be marked up and sold to end customers. Eaton will also sell certain transmission components to the joint venture at prices approximating market rates. In addition, Eaton will provide certain manufacturing and administrative services to the joint venture, including but not limited to manufacturing labor in Mexico, information technology services, accounting services and purchasing services, at prices approximating market rates. Pro forma financial information was not provided as historical activity related to the products contributed to the joint venture was not material.
We consolidated the results of the joint venture in our Components segment as we have a majority voting interest in the venture by virtue of a tie-breaking vote on the joint venture's board of directors. The joint venture had an enterprise value at inception of $1.2 billion. Due to the structure of the joint venture and equal sharing of economic benefits, we did not apply a discount for lack of control to the noncontrolling interests. The preliminary purchase price allocation was as follows:
Total business valuation
Less: Noncontrolling interest
Total purchase consideration
Customer relationship assets represent the value of the long-term strategic relationship the business has with its significant customers, which we are amortizing over 25 years. The assets were valued using an income approach, specifically the "multi-period excess earnings" method, which identifies an estimated stream of revenues and expenses for a particular group of assets from which deductions of portions of the projected economic benefits, attributable to assets other than the subject asset (contributory assets), are deducted in order to isolate the prospective earnings of the subject asset. This value is considered a level 3 measurement under the GAAP fair value hierarchy. Key assumptions used in the valuation of customer relationships include: (1) a rate of return of 10 percent and (2) an attrition rate of 3 percent. Technology assets primarily represent the associated patents and know how related to the Endurant and Procision next generation automated transmissions, which we are amortizing over 15 years. These assets were valued using the "relief-from-royalty" method, which is a combination of both the income approach and market approach that values a subject asset based on an estimate of the "relief" from the royalty expense that would be incurred if the subject asset were licensed from a third party. Key assumptions impacting this value include: (1) a market royalty rate of 5 percent, (2) a rate of return of 10 percent and (3) an economic depreciation rate of 7.5 percent. This value is considered a level 3 measurement under GAAP fair value hierarchy. Annual amortization of the intangible assets for the next 5 years is expected to approximate $28 million.