The CME Group, the world’s biggest futures exchange, is under fire from a fledgling rival that accuses it of blocking competition by refusing to accept futures contracts from other trading venues and to allow trades transacted at the CME to be cleared elsewhere.

ELX – which is backed by some of Wall Street’s biggest names, including Deutsche Bank, Credit Suisse, Bank of America-Merrill Lynch and JPMorgan – this week received approval from the Commodity Futures Trading Commission, the US futures watchdog, for “Exchange of Futures for Futures” (EFF) trades, in which traders can translate trades from one futures exchange to another through a private, off-exchange transaction.