Futures-exchange operator CME has agreed to pay a fine of up to $4m to settle a long-running lawsuit with its regulator over accusations that former exchange employees leaked confidential trading information.

The Commodity Futures Trading Commission brought the case in 2013 against a CME unit, the New York Mercantile Exchange, and two former employees of the unit, known as Nymex. The CFTC accused the former employees of disclosing private information on client activities to a commodities broker in return for meals and entertainment. The regulator later added the broker as a target of its civil lawsuit.