SOUTH MILWAUKEE, Wis. (AP) â¿¿ Caterpillar Inc.'s planned buyout of Bucyrus International Inc. has cleared a U.S. antitrust review. The companies said Friday that the U.S. Department of Justice has cleared the acquisition, valued at $8.6 billion including net debt. Caterpillar and South Milwaukee-based Bucyrus say the clearance will allow the acquisition to proceed as soon as all other conditions to closing have been satisfied. The deal is expected to close in mid-2011. Caterpillar will fund the acquisition through a combination of cash from its balance sheet and debt. Caterpillar does not plan to issue equity to help pay for the acquisition. Bucyrus makes surface mining equipment used for coal, copper, iron ore, oil sands and other minerals. Caterpillar, based in Peoria, Ill., is the world's largest construction- and mining-equipment maker.