Although Washington's Howrey & Simon and Houston firm, Arnold White & Durkee officially joined forces this week, the latter's Austin and Chicago offices will not be part of the new firm.
Lawyers in these offices say they have different aims and chose not to partake in the merger.
The new firm will be headquartered in Washington DC and have offices in Houston, Los Angeles and Menlo Park, with a total of 440 attorneys – 230 of them IP lawyers.
The new firm – understood to be called Howrey Simon Arnold & White – will open for business on January 31.
John Lynch, the former managing partner of Arnold White & Durkee, will reportedly head up the IP group from the Silicon Valley office, while James Davis, the former head of IP at Howreys, will be retiring.
Howrey & Simon's Ralph Savarese will be chairman of the new firm and Robert Ruyak the managing partner and CEO.
Ruyak told The Lawyer last year (Sept 13) that the merger was prompted by the growth in technology litigation in the US and Europe and that plans are afoot to open offices in London, Brussels and Geneva.
He said: "Now we have law firms we use as associates with us. But we are going to be looking at establishing in Europe.