Financial terms were not disclosed, however Onex Partners targets investment opportunities that require $200m or more of initial equity capital.
Compass pays €100m for education recruiter Protocol and Bridgepoint's remaining stakes in two other businesses Compass bought from it in 2016.
Heyworth joins as head of finance from Investec where he was group financial controller.
Cabot Square acquired LDF from Investec in 2013 and built the business up from a small business finance broker into an established challenger lender.
Wathen joins Livingbridge as an associate director from Pentland Group where she focused on the firm’s venture investments portfolio.
Launched by DeA Capital, IDeA Agro will invest mainly in medium-sized and large agricultural production companies.