Research In Motion Ltd., the Canadian company that makes the phones, said users in the Americas "may be experiencing intermittent service delays this morning," and said it's working to fix the problem.
Bell Canada spokesman Mark Langton said some BlackBerry users at all Canadian carriers were affected.
Overseas, the problems started Monday, leaving many BlackBerry owners exasperated. On Tuesday, RIM said a crucial link in its infrastructure had failed, and a backup didn't work either. It said it was now working to get through a backlog of traffic.
The service outage, the longest in many years, added to RIM's woes. The company is struggling with slowing sales and a tablet that's been a dud. Its shares are approaching a five-year low.
In the United Arab Emirates, the two biggest phone companies said they would compensate their BlackBerry users for the mishap by giving them at least three days of free service. Matthew Willsher, chief marketing officer for Etisalat, the country's biggest telecom, said it was acting in response to the "exceptional and unprecedented circumstances."
Unlike other cellphone makers, RIM handles email and messaging traffic to and from its phones. That allows it to provide services that other phones don't have, lets it optimize data service and provide top-class security. But when it encounters a problem, a large share of the 70 million BlackBerry subscribers worldwide can be affected all at once. BlackBerry outages tend to occur several times a year, but they usually last for less than a day.
One of the BlackBerry's big attractions is the BlackBerry Messenger, or BBM, which works like text messaging but doesn't incur extra fees. That service was affected by the outage, and to make matters worse for RIM, Apple Inc. is releasing software Wednesday for its iPhones that works like BBM. Competition from Apple is one of the chief causes of RIM's diminishing fortunes.
RIM shares fell 42 cents, or 1.7 percent, to $23.99 in morning trading in New York as major indexes rose.