Senior sources at Calpers, the world's biggest pension fund, say it is reviewing its close relationship Eric Knight, the Monaco-based active investor currently attacking HSBC.

The prospective changes came to light as Calpers lost its chief executive and chief investment officer. The giant fund, parted company with another of its most senior fund managers in February.

Knight has had a close relationship with Calpers for the past five years. The pension fund owns a 33% stake in his Knight Vinke Asset Management (KVAM ) firm. Last year, KVAM underperformed its benchmark although it has made big returns for Calpers in the previous four years.

Knight forged a close relationship with Fred Buenrostro, the outgoing Calpers chief executive, Russell Read, the departing chief investment officer, and Christy Wood, the former top fund manager.

But, with all three leaving, the board is expected to announce big strategy changes. A senior Calpers source said: “We are now looking at all the relationships we have with corporate governance funds because a number of them have underperformed.”

KVAM said last month that Calpers “values very highly” their relationship. It said it had increased its funds under management fivefold last year, indicating big investors were “a testimony to their belief in the merits of our analysis”.