The quarterly rankings of UK-listed companies saw FD maintain its lead over Buchanan Communications and Brunswick.
FD lost two clients, dropping to 171 in the three months up to November 5.
Buchanan gained 14 clients over the period to climb to 146 accounts with Brunswick dropping five to 88.
Citigate Dewe Rogerson has 83 clients with both College Hill and Pelham PR on 75.
Brunswick does have over a quarter of FTSE 100 companies on its books with 27. The only close challenger is Finsbury with 21 - Maitland is the only other agency in double figures with 10.
Buchanan again tops the rankings for AIM clients, with FD serving the most FTSE 250 companies.
