CME Group Inc.'s decision to allow users of its interest-rate swap future contracts to avoid tougher oversight is drawing scrutiny from its government regulator.

The contracts, which begin as futures and are converted to swaps guaranteed by CME's clearinghouse if held until delivery, won't be included in totals determining whether users face higher collateral, capital and trading requirements, Laurie Bischel, a CME spokeswoman, said. Under Commodity Futures Trading Commission rules, traders who buy or sell more than $8 billion of swaps in a year will face the tougher standards by being designated a dealer or so-called major-swaps participant.

“CFTC is currently reviewing this product, and we have not yet taken a view on whether the resulting swap counts toward a market participant's status as a dealer or major-swap participant,” Steve Adamske, a CFTC spokesman, said in an e-mailed statement. “Market participants are urged to consult the rules in order to determine whether certain products would be in compliance with CFTC swap regulations.”