The world's biggest banks pressed policymakers to pass an urgent Brexit fix, to ensure European traders ongoing access to London derivatives clearinghouses and avoid rupturing 61 trillion pounds ($78 trillion) in contracts.

The industry's top lobbying associations told the European Commission, the European Union's (EU's) executive arm, that it must act fast or risk turmoil when the stopgap solution elapses in March. The call echoes pressure on the EU from the Bank of England, which has said firms might need to move business out of London as early as next month unless there is clarity.

"We respectfully but urgently request the Commission to provide this confirmation well in advance of the end of December 2019," the FIA, which represents banks, brokers, and other firms in the derivatives markets, said in a letter. The International Swaps and Derivatives Association (ISDA), the Association for Financial Markets in Europe, and 11 other industry bodies also added their signatures.