OKLAHOMA CITY ? A federal judge has ruled that the Federal Trade Commission overstepped its authority in creating the national “do-not-call” list against telemarketers.

The ruling came in a lawsuit brought by telemarketers who challenged the list of 50 million people who submitted their telephone numbers and said they do not want to receive business solicitation calls.

The immediate effect of Tuesday’s ruling given by U.S. District Judge Lee R. West was not clear. He did not immediately issue an order directing an action by the FTC.

The list was to go into effect Oct. 1.

The ruling only affects the national list and does not void state lists, like the one Kansas has in place.

The judge said the main issue in the case was “whether the FTC had the authority to promulgate a national do-not-call registry. The court finds it did not.”

West said the 1994 Telemarketing and Consumer Fraud and Abuse Prevention Act gave the Federal Communications Commission, not the FTC, the authority to operate a national database of people who object to receiving telephone solicitations.

The FTC, however, said the Omnibus Appropriations Act, signed by President Bush this past February, authorizes it to “implement and enforce the do-not-call provisions of the Telemarketing Sales Rule.”

“This decision is clearly incorrect,” FTC Chairman Timothy Muris said Wednesday. “We will seek every recourse to give American consumers a choice to stop unwanted telemarketing calls.”

House Energy and Commerce Committee Chairman Billy Tauzin, R-La., and Rep. John Dingell, D-Mich., said Wednesday they were confident the ruling would be overturned.

“Contrary to the court’s decision, we firmly believe Congress gave the FTC authority to implement the national do-not-call list,” they said in a joint statement. “We will continue to monitor the situation and will take whatever legislative action is necessary to ensure consumers can stop intrusive calls from unwanted telemarketers.”

Direct Marketing Assn., one of the plaintiffs, said it was happy with the ruling, even though it “acknowledges the wishes of millions of U.S. consumers who have expressed their preferences not to receive telephone-marketing solicitations — as evidenced by the millions of phone numbers registered on the FTC list.”

The telemarketing industry estimates that the do-not-call list could cut its business in half, costing it up to $50 billion in sales each year.