WASHINGTON (Reuters) - Lawmakers scurried to reinstate the national "do not call" list on Wednesday after a U.S. court blocked the popular program, which would allow consumers to stop most telemarketing calls.

The Oklahoma City judge's decision could derail an initiative that promised dinnertime peace for millions of families frazzled by unsolicited sales calls. It was due to take effect Oct. 1.

In a decision filed late on Tuesday, U.S. District Judge Lee West said the Federal Trade Commission overstepped its authority when it enabled consumers to place their home and mobile phone numbers off-limits to telemarketers.

The FTC said it would appeal, and Congress promised immediate action.

Telemarketers would have faced fines of up to $11,000 per call if they phoned any of the 50 million phone numbers collected by the FTC.

The FTC asked the court to allow the program to take effect while it appeals the decision, and several lawmakers said they would try to reinstate it by next week.

Both houses of Congress will vote on bills to reinstate the program on Thursday, aides to congressional Republican leaders said.

Rep. Billy Tauzin, chairman of the House of Representatives Energy and Commerce Committee, predicted that Congress will quickly have a bill ready for the president's signature.

"This will get cured tomorrow," the Louisiana Republican said on CNN.

Several telemarketing firms and the Direct Marketing Association sued to block the measure in January, saying it would violate free-speech laws and decimate the industry.

In his decision, West said existing laws give the FTC authority to curb abusive telemarketing practices, but any national do-not-call list must be handled by the Federal Communications Commission.

The question raised by the lawsuit is "whether the FTC had the authority to promulgate a national do-not-call registry. The court finds it did not," West wrote.

West said the FTC does have authority to limit how telemarketers acquire customer lists and use automatic-dialing software.

FTC DEFENDS LIST

The Direct Marketing Association welcomed the decision and said consumers could sign up for its own do-not-call list, which does not penalize violators. Consumers can sign up online for $5 or mail in an application for no charge.

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

Muris did not say whether the agency would turn over the list to the FCC, but FCC Chairman Michael Powell said such a move would not be necessary.

"I don't think it's going to come to that," Powell told Fox News. "I think our legislators and our administrators are going to work very quickly to make sure that jurisdiction is properly vested."

Lawmakers leapt to defend the hugely popular program, with many noting that they too had placed their telephone numbers on the list.

"If this decision is not reversed quickly, I suspect the courthouse in Oklahoma would want to add itself to the do-not-call database in order to protect itself from the millions of consumers who feel deeply about the right to be left alone by telemarketers," Massachusetts Rep. Ed Markey said.

"This is the goofiest decision that I've seen in a long time," said New York Sen. Charles Schumer.

At least 27 U.S. states, including Oklahoma, have do-not-call lists of their own. Those will continue to operate even if they have been merged with the national list, state officials said.

Another trade group, the American Teleservices Association, has challenged the do-not-call list in a U.S. court in Denver.

(Additional reporting by Jeremy Pelofsky and Susan Cornwell in Washington and Jonathan Herskovitz in Dallas)