Update 7:18 a.m.: Research in Motion says BlackBerry service has been fully restored.

VANCOUVER (NEWS1130) – Research In Motion says BlackBerry service has been fully restored.

The company says it was working around the clock to clear backlogged email messages stuck in its system after the largest BlackBerry outage ever.

The widespread outage in Canada and the US started Monday. Users were without email, texting, and BBM (Blackberry messaging) — sparking a flurry of complaints on Twitter. In Vancouver, #blackberry was trending today, for the second day in a row. Some tweets include:

Dear Blackberry, do you know what the #iPhone said to the #Blackberry? … “iWork”

Dear #Blackberry thank you for honouring Steve Jobs with a 3 day silence

The BlackBerry outage — the biggest in the company’s history — even reached Prime Minister Stephen Harper‘s office. Andrew MacDougall, spokesman for the prime minister, took to social networking site Twitter yesterday and tweeted: “Am being impacted by RIM/Berry service outage — please call if you need to reach me.”

RIM says a “core switch failure” in Europe caused the global service outages and the original outage caused a backlog of messages, which then spread around the world. CTO for software for RIM, David Yach, adds there were backup systems in place but they failed to kick in.

“It’s a huge embarrassment for a company that has built its reputation on the notion of service and reliability and when all else fails your BlackBerry will still work,” says Michael Gartenberg, director of research at US-based technology firm Gartner Inc.

He adds the outage comes at a key time for the company. “It’s coming at a time when RIM is facing increasing competition from companies like Google and Apple and Microsoft, all launching new products.”

RIM has been losing ground in the hyper-competitive North American market to Apple and Android devices in recent years. Although it’s still a leader in the business market, Apple has been making inroads with corporations.

Apple’s new iPhone 4S, announced last week, is set to hit stores tomorrow.

But Duncan Stewart, director of research at Deloitte Canada tells us although the outage is annoying, it is not necessarily a major black eye for RIM. “It’s much easier to write a story about another thing going wrong with BlackBerry. That doesn’t mean their outages are more severe or worse than other carriers.”

The same outage hit Europe, the Middle East, parts of Asia, and South America over the long weekend

In a letter posted yesterday on RIM’s website Robin Bienfait, RIM’s chief information officer, apologized for service interruptions and delays.

“You’ve depended on us for reliable, real-time communications, and right now we’re letting you down. We believe we understand why this happened and we are working to restore normal service levels in all markets as quickly as we can.”

However, an apology didn’t seem to be good enough for the government of Colombia, which reportedly asked RIM to compensate users affected by the glitches.