The encrypted message service run by Canada's Research In Motion (RIM) for BlackBerry users - a lifeline for corporate executives - was hit by a network problem three days ago.
The messaging and browsing delays being experienced in India, Europe, West Asia, Africa, Brazil, Chile and Argentina were caused by a fault in RIM's infrastructure, the company said in a statement.
RIM said it did not give region-wise numbers of users, but there are 60 million BlackBerry service users worldwide. Of them, 40% are corporate or institutional users.
The service is also increasingly popular among college students and youths after RIM opened itself to non-corporate consumers.
Arjun Chatterjee, CEO of IT firm RunTime Solutions, is worried how he will receive key official messages when he reaches Pune on Friday.
He has the company of superstar Amitabh Bachchan, who tweeted: "BLACKBERRY ...!!! What does one do to get you up again!!??"
"The BlackBerry outage has resulted in a slowdown of corporate decision-making," said an executive of Tata Steel.