European derivatives trading platforms are still unclear about how to meet strict US rules that will allow them to continue accepting business from US firms, despite the Commodity Futures Trading Commission giving them more time to demonstrate compliance.

Operators of European platforms, the vast majority of which are based in London and regulated by the Financial Conduct Authority, were initially given until March 24 to make their platforms compatible with US rules and register them with the CFTC, the lead US derivatives regulator.