Gibson Dunn has hired U.S. rival O'Melveny & Myers' Brussels managing partner, the day after O'Melveny's proposed tie-up with Allen & Overy was called off.

Christian Riis-Madsen, who had been at O'Melveny since 2004, will work in Gibson Dunn's antitrust and competition team.

Prior to joining O'Melveny, Riis-Madsen was an associate with Norton Rose in Brussels for three years, and started his legal career at Danish law firm Kromann Reumert in 2000.

His practice focuses on EU competition and regulatory law for high-tech industries involving fast-evolving markets, intellectual property rights, and complex trade patterns.

Peter Alexiadis, partner in charge of Gibson Dunn's Brussels office, said in a statement: "Christian has been on our radar for some time. His reputation in the high-tech sector fits very well with our existing client base, while significant synergies also present themselves in the growth of our existing Scandinavian/Nordic practice."

The news of his hire comes the day after O'Melveny's nearly 18-month-long merger talks with Magic Circle firm Allen & Overy were called off.

The firms decided not to move forward with a merger, with two people citing adverse macroeconomic conditions that would impact the value of a tie-up.

Earlier this year, Riis-Madsen took a role advising on the transfer of assets into a private equity fund backed by U.K. private equity secondaries firm Coller Capital, a client of the firm.

His departure from O'Melveny follows that of London-based funds partner John Daghlian, who joined Akin Gump Strauss Hauer & Feld in a move that reunited him with former colleagues Daniel Quinn and Aleksander Bakic. Bakic and Quinn joined their new firm in April, at the same time as fellow funds partner Eve Ellis joined Ropes & Gray's City office.