Brussels, Belgium

Steptoe & Johnson has hired David O'Sullivan, a former EU ambassador to the United States, as senior counsellor in its Brussels office.

O'Sullivan knows the U.S. administration and politics very well from five years as the bloc's ambassador, and how the EU works from his time as head of the European Commission's administration, head of the trade department and of the bloc's foreign service.

Steptoe chairman Phil West said in a statement: "Ambassador O'Sullivan is a highly respected senior EU official who has had a brilliant career in the European Commission.

"The various positions he has held have given him almost unparalleled insight into the full range of transatlantic business issues, including trade policy, cybersecurity and Brexit, among others. His arrival reinforces the strength of our Brussels office as a resource for clients doing business in Europe across a range of EU issues."

O'Sullivan, who is Irish, served as head of the EU's delegation to the U.S. and later ambassador, from 2014 to 2019. This was during President Barack Obama's second term and two years of President Donald Trump's term. Before that, he was chief operating officer of the European External Action Service, the EU's foreign service, from 2011. O'Sullivan was director-general in the European Commission's trade department from 2005 to 2010 and before that, head of the private office of European Commission President Romano Prodi in 1999.

Ruxandra Cana, managing partner of Steptoe's Brussels office, said in a statement: "Ambassador O'Sullivan has acquired knowledge of the substantive issues that are at the core of EU relations with the United States, as well as a number of the other major trade and diplomatic relationships of the European Union and its member countries… His exceptional background complements the more than 30 years' experience of our lawyers in Brussels."

Asked why he joined Steptoe over other international law firms, O'Sullivan said: "Steptoe impressed me in the sense of being on the same page."

O'Sullivan said it was also the scope of work offered by Steptoe that attracted him. "It was a good fit," he said, referring to the compliance and regulatory work offered by the position. He said he will be advising Steptoe's legal team and clients on a range of subjects, including World Trade Organization and transatlantic trade issues.

He added that one factor in joining Steptoe was that the firm wanted to expand its client offering to include public affairs.

On the rules for former EU officials joining private sector companies, O'Sullivan said his plans to join Steptoe had been approved by the body responsible for vetting job moves. He explained that he is not allowed to lobby former colleagues in the EU institutions and can't work on files he dealt with during his time as an EU civil servant, for 12 months after leaving the EU's public service.

In March, Arnold & Porter Kaye Scholer hired Alexander Italianer, a former head of the European Commission's civil service and antitrust department, to its Brussels office.