For Mayer Brown, specialists in electronic discovery and appellate work were the sec­rets to success during 2012. The firm's Chicago lawyers pulled in significant wins before the U.S. District Court for the Northern District of Illinois and the U.S. Supreme Court.

"I think there are a lot of great firms in Chicago," said Mayer Brown partner Andrew Marovitz, a Chicago-based co-leader of the litigation group worldwide. "But I don't think there are many that can marry the disciplines" that Mayer Brown brings.

In Illinois, a Mayer Brown team led by Marovitz and partner Britt Miller, a co-leader of the Chicago litigation practice, in 2012 secured support for the principle that a party producing documents during electronic discovery can't be told how to secure the production of the material. The firm represented packaging products company Temple-Inland Inc. in the closely watched dispute that arose out of Kleen Products LLC v. Packaging Corp. of America, a case involving price-fixing in the packaging products industry.

Before the Supreme Court, Chicago partner Stephen Shapiro, founder of the firm's Supreme Court and appellate litigation practice, successfully argued for Mayo Collaborative Services Inc. in Mayo Collaborative Services v. Prometheus Laboratories Inc. The court last year ruled unanimously that a diagnostic process used in connection with the treatment of autoimmune diseases was not patentable. — Andrew Ramonas