Caterpillar relied on a trio of Am Law 100 firms to advise the company on its $7.6 billion acquisition of mining equipment manufacturer Bucyrus International. Bucyrus turned to two of its own top legal advisers for the all-cash transaction, which when including debt, is valued at $8.6 billion.

Mayer Brown M&A partners John Sagan and William Kucera in Chicago took the lead advising Peoria, Ill.-based Caterpillar along with corporate associates Andrew Noreuil, Rachel Spehler, and Joseph Hable. Last month Mayer Brown advised Caterpillar on its $810 million acquisition of German engine maker MWM Holding. In June, Caterpillar tapped the firm for counsel on its $820 million purchase of locomotive maker Electro-Motive Diesel. Mayer Brown’s relationship with the company began in 2004.