Some of the world's biggest companies and U.S. market watchdogs locked horns on Wednesday on legislation to regulate the opaque $450 trillion private swaps market.

With only a few days left to voice complaints, large companies that use derivatives to hedge their risk and federal market regulators pushed Congress for changes to a draft bill.

The House Financial Services Committee has tentatively scheduled a three-day bill drafting session for next week, where it is likely to vote on the new derivatives rules.