Users of interest-rate and credit swaps will have until July 1 to comply with the reporting rule, according to the CFTC statement. The deadline for users of equity, foreign exchange and other commodity swaps was extended until Aug. 19. Non-financial counterparties gained an extension to Oct. 31 for certain reporting requirements for all swap asset classes.

“I am troubled by the arbitrary and ad-hoc manner in which this relief was provided,” CFTC Commissioner Scott O'Malia, a Republican, said in a statement. “The application of date, product and participant distinctions makes compliance and implementation confusing for the end users.”

The CFTC and Securities and Exchange Commission are implementing derivatives provisions of Dodd-Frank, the 2010 regulatory overhaul, after largely unsupervised trades helped fuel the 2008 credit crisis. New rules planned for the $639 trillion global swaps market require that trade information be reported to so-called swap data repositories that function as central record-keepers.