The chambers of 11 Bolt Court and 7 Stone Buildings have merged to create a 45-tenant set.
The set does not yet have a new name or premises – although both are under urgent review.
After a number of failed investigations into other sets, 11 Bolt Court entered negotiations with 7 Stone Buildings in April.
The new set will be run by a management committee consisting of three senior tenants from each set and chaired by 11 Bolt Court's current chairman Simon Randle.
It is already planning further expansion.
“I would be amazed if numbers didn't grow quite substantially,” says Randle.
Randle, a local government law specialist who acted for the Department of Transport in the Heathrow Terminal 5 inquiry, says that the economies of scale of a larger set means more money can be invested in specialist clerking teams.
A new senior clerk will be appointed to handle the day to day running of the new teams, one for each of the four different practice groups – family, crime, civil and local government.
John Lister, 11 Bolt Court's chambers director, retains his current title and takes overall responsibility for clerking and administration but will concentrate mainly on business development.
John Bishop, who has been head of chambers at 7 Stone Buildings for nearly 15 years, is standing down to concentrate on his practice.
11 Bolt Court is also the first set of chambers to be recommended for the BarMark, following a successful audit by the British Standards Institute.