The court, without comment, let stand a 10th U.S. Circuit Court of Appeals decision that upheld the registry of more than 64 million phone numbers as a reasonable government attempt to safeguard personal privacy and reduce telemarketing abuse.

Under the 2003 federal law, businesses face fines of up to $11,000 if they call people who sign up for the registry - unless they have recently done business with them.

Charities, pollsters and callers on behalf of politicians, however, are exempt.

Telemarketing groups had filed the appeal, arguing in filings that the registry violated First Amendment rights because it singled businesses out while exempting other groups.

They also said 2 million of their 6.5 million workers will lose their jobs within two years if the do-not-call rules stand.

A federal judge in Denver agreed with the telemarketers, but the circuit court upheld the registry in February 2004 after concluding that there was no evidence suggesting that charitable or political callers were as intrusive to consumers' privacy.

Officials with the American Teleservices Association did not return phone calls that were placed Monday.