Many users had reported not being able to receive or send email, use instant messaging or browse the Internet, though the problems did not appear to be the same for each user, or affect all users.

Canada-based Research In Motion (RIM), the maker of BlackBerry, said in a statement late Monday that all services had been restored and apologized again for any inconvenience.

The company has not said what caused the problem.

RIM has struggled this year with weaker sales of the BlackBerry smartphone against rivals like Apple's iPhone, various models from HTC, and other handsets running Google's Android software.

The company's share price fell 0.56 percent to $23.23 Monday after the outage news, and was down 60 percent from the beginning of the year.