NEW YORK— A major service outage afflicted users of the popular, addictive BlackBerry smart phones across the United States and Canada today, wireless carriers said.

Officials with AT&T Inc. and Verizon Wireless said BlackBerry maker Research in Motion Ltd. told them customers of all wireless carriers were affected.

It was not immediately clear how many BlackBerry subscribers had problems, as some users reported being able to access their service normally this afternoon.

The BlackBerry service, which lets users check e-mail and access other data services on their handheld devices, has become a lifeline for many business executives and is increasingly popular among consumers with models like the BlackBerry Pearl.

There was no word what caused the outage or when service would be restored.

RIM officials did not return phone calls.

Major disruptions have been rare but often provoke an angry backlash against the Canadian company because of its typically lengthy silences about the cause and because it eventually gives only cryptic, jargon-laden explanations.

When the BlackBerry service suffered a major outage last April, the company remained silent about the cause for two days.

In a statement, AT&T spokesman Fletcher Cook said the company first learned about the problem from RIM at about 3:30 p.m. EST.

"This is not an issue with AT&T's wireless network," Cook said. "Customers could experience difficulties using their BlackBerry devices. RIM has not given us an estimated time of when this problem would be fixed."

RIM is based on Waterloo, Ontario, and has deals with scores of wireless carriers to offer the BlackBerry service around the world.