The Bush administration is trying to finalize rules on Internet gambling before leaving office.
The regulation has already been reviewed by the White House budget office, which is usually the last step before being published in the Federal Register.
The law passed two years ago to clamp down on Internet gambling has proven confusing. For one thing, it doesn't clearly define Internet gambling. Financial institutions say that's complicated the effort to block payment of online gambling debts.
The new regulation from the Treasury Department does not attempt to define illegal online gaming.
A top Democrat says such "midnight rulemaking" will only tie the hands of the new administration, and burden the financial services industry in a time of economic crisis.