The Bush administration will not immediately create a national do-not-spam registry (search) to discourage unwanted e-mails, saying using current technology to do so might even generate more unsolicited sales pitches across the Internet, according to documents obtained Tuesday.

The Federal Trade Commission (search), expected to announce its decision later Tuesday, said it feared that unscrupulous senders of unwanted e-mails would mine such a registry of e-mail addresses to look for new victims, according to a summary of the FTC's decision obtained by The Associated Press.

The commission, which was obligated to consider the proposal under the "can spam" legislation that Bush signed in December, concluded that it would be "largely powerless to identify those responsible for misusing the registry."

Regulators instead proposed broad adoption of new authentication technology that will make it more difficult to disguise the origin of unwanted e-mails. Several proposals from leading technology companies, including Microsoft Corp. (MSFT), are under industry consideration.

"A national do-not-e-mail registry, without a system in place to authenticate the origin of e-mail messages, would fail to reduce the burden of spam and may even increase the amount of spam received by consumers," the commission said.

The government said it was particularly worried about issues of security and privacy with respect to children whose addresses might be added to such a registry.

"A registry that identified accounts used by children, for example, could assist legitimate marketers to avoid sending inappropriate messages to children," the commission said. "At the same time, however, the Internet's most dangerous users, including pedophiles, also could use this information to target children."