The main U.S. swaps regulator risks harming American firms with the way it's telling international counterparts to interpret rules to oversee the $648 trillion swaps market, according to executives at brokers from ICAP Plc to Tradition North America Inc.

The Commodity Futures Trading Commission is weighing final guidance on the cross-border reach of trading, capital, collateral and other swaps rules under the Dodd-Frank Act. The commission held a meeting in Washington last week with the U.S. Securities and Exchange Commission, which shares oversight of some swaps markets, where European regulators said the U.S. approach wouldn't work.

"It's actually very evident that a lot of what the CFTC has done is harming the U.S.," Mark Beeston, chief executive officer of portfolio risk services for ICAP, said yesterday on a panel discussion at the SefCon III conference in New York.