Berkshire Hathaway announced on Monday that it’s acquiring 77 percent of railroad operator Burlington Northern Santa Fe for $34 billion in cash and stock. Berkshire, the holding company for the assets of Warren Buffett, the world’s second-richest man, already owns the other 23 percent.

Cravath, Swaine & Moore, Munger, Tolles & Olson and Sullivan & Cromwell worked on the deal — the largest in Berkshire’s history.