Tru-Est chairman and editor-in-chief James Anderson said it had brought in Polhill at the end of last month following a five-way pitch.
'We realised that if we tried to raise our profile on our own it wasn't going to work,' said Anderson.
Tru-Est publishes PAM (Private Asset Managers) in its UK and international editions. The guide has information on private wealth managers and analyses the private wealth market.
Tru-Est also runs consumer site PAMonline.com and daily news service thewealthnet.com.