Usher left SJ Berwin to join the Edinburgh office of D&W as head of EU competition in January 2004.
At the time he had hoped to base the majority of his work out of Edinburgh, but the nature of his work and client base has meant his activity has continued to be predominantly London-based.
Usher, who has acted for clients including William Hill and Ladbrokes, will now rejoin SJ Berwin’s London office, where he had previously been with since 1999.
SJ Berwin suffered a triple partner defection at the time of Usher’s loss last year, also losing highly rated private equity partner John Daghlian to O’Melveney & Myers and property partner Sally Pinkerton to Wragge & Co.
At the time the firm was described as being “pretty devastated” by Usher’s departure.