Chicago firm Piper Marbury Rudnick & Wolfe is in merger talks with California's McCutchen Doyle Brown & Enersen to create a 1,200-lawyer firm.
Piper Marbury was formed in 1999 with the merger of Chicago's Rudnick & Wolfe and Baltimore's Piper Marbury. At the time it was the largest domestic merger in US history. The firm has nearly 900 lawyers, compared to 300 at McCutchen Doyle.
The two firms have been in talks since the end of last year and have just signed an agreement to speak only to each other.
McCutchen Doyle's managing partner Michael Plishner says: "I would say that the talks are at a preliminary stage. We've agreed to talk to each other exclusively because of potential synergies that we see. We've a long way to go before we actually have a deal put together, but both firms have seen the great possibilities of a large law firm."
He adds that if the deal goes ahead he expects it to be completed this autumn.
The merged firm's largest office would be Chicago with 300 lawyers, it would have 300 lawyers on the West Coast, 100 in New York and 400 lawyers based in Washington DC, Baltimore and West Virginia.
McCutchen Doyle also has an affiliated law firm in Taipei, with J&J Law Firm, making 12 offices in total.
Plishner says that there are a raft of synergies between the two firms. He says: "The overlaps really are in a whole bunch of areas, we both have very large litigation practices and we both have very significant intellectual property practices focusing both on biotechnology and electronic computer technology.
"The business practices are very much focused on technology and emerging companies, and we have environmental practices which fit together."
McCutchen Doyle's client list includes a host of Fortune 100 companies with many high-tech clients such as Microsoft and Amazon. Piper Marbury is known for its leading commercial real estate department, which is one of the best in the country.
The talks follow hard on the heels of the merger between San Francisco's Pillsbury Madison & Sutro and New York's Winthrop Stimson Putnam & Roberts, which was sealed at the start of the year (The Lawyer, 8 January).
That was one of the most significant link-ups between firms on both coasts, boasting more than 200 securities, finance and technology lawyers on each side of the country.