WASHINGTON (Reuters) - A U.S. Federal Trade Commission rule takes effect on Wednesday that will hit energy traders and companies with fines of up to $1 million a day if they manipulate the oil markets.

The FTC unveiled the rule back in August to go after fraud in oil markets that it said could cause widespread damage to the U.S. economy. The old fine was just $11,000.

The rule prohibits fraud or deceit both in the cash, or physical, energy markets and on the regulated futures exchanges.