Europe's financial regulator has identified potential weaknesses at two of the region's big clearing houses, drawing fresh attention to companies now widely considered to be systemically important to the safety of global markets.

The Paris-based European Securities and Markets Authority said today that its second-ever stress test of  EU clearing houses had raised concerns about Spain's BME Clearing and ICE Clear Europe, which is owned by the Intercontinental Exchange; its concerns relate to how they would handle the default of bank members in plunging markets in a particular scenario.