Brian advises in relation to anti-trust, mergers, and state aid. Brian acts for claimants, defendants, and regulators and has also advised the European Commission. Brian has particular expertise in regulatory matters and in private antitrust damages actions.

Brian has also advised tribunals and government agencies in Ireland, Hong Kong, and the Cayman Islands. Brian was appointed to the Attorney General's B Panel in March 2009 and has a particular expertise in the EC and regulatory field.