The Big Four firm has now 149 AIM clients, after losing just one client in the last three months.
BDO, the only top ten auditor to add to its AIM client count, retained second place with 144 clients (143 in October), Grant Thornton was in third, with 130 (same as in Q4 2016), and PwC fourth with 104 clients (106). Deloitte had the fifth most with 62, compared to 64 in October.
Within the FTSE AIM 100 and FTSE AIM 50 clients, PwC topped both rankings, with 29 and 15 clients respectively.
The mid-tier firm BDO was the auditor of choice to basic material businesses with 30 clients, more than half of clients than Grant Thornton, the second firm in the ranking, with 14 clients.
BDO was also the number one auditor for consumer goods businesses, with 11 clients, followed by PwC with 9, and for oil and gas businesses.
Meanwhile, consumer services and financial clients continued to prefer KPMG as their auditors. The firm had 38 financial clients in the first quarter of the year, one more from the previous quarter.
The firms Chapman Davis and Rees Pollock entered the financial clients ranking for the first time after securing two clients.