Regulators could increase systemic risk if they are too prescriptive regarding the type of instruments clearing houses can accept as collateral under new rules being drawn up by US and European regulators, clearing houses have warned. The comments underline the growing debate regarding how clearing houses manage risk at a time when clearers are becoming increasingly critical to the financial system.

Speaking yesterday at IDX, London's annual derivatives conference, a raft of US and European clearing house chiefs said that regulators could introduce new risks into the financial system if the rules regarding clearing house collateral are too restrictive.