Planning and commercial set 4-5 Gray’s Inn Square has followed a strong financial year with the hire of a new tenant.

Thomas O’Riordan joins the set on Monday (6 June) from US firm Cawalader Wickersham & Taft where he continues to be a retained counsel. Prior to Cadwalader, O’Riordan was head of Nomura’s transactional legal department in London. He specialises in regulatory and financial services work.

O’Riordan joins 4-5 Gray’s Inn Square as the chambers announced an 11 per cent increase in income for the last financial year. Turnover exceeded £12m for the first time, up from last year’s £10.8m. Revenue per barrister rose by the same amount to £273,000 from £244,000.

Senior clerk Michael Kaplan said O’Riordan’s hire would boost the set’s regulatory practice. Hodge Malek QC has done a large amount of work for the Financial Services Authority (FSA) and several of the set’s junior tenants also work in the area.

“Regulatory law is a growing area, and is something we as a chambers are keen to do more of,” said Kaplan.

4-5 Gray’s Inn Square has not traditionally had a relationship with Cadwalader.

Recently the set lost commercial and insurance junior Geraldine Clark to Serle Court.