According to data supplied by GfK, the struggling BlackBerry accounted for 26.3% of UK smartphone sales in December 2011, while the range averaged a 27.7% share through the year.
BlackBerry hit 8.5 million subscribers in Britain by the end of 2011, while its worldwide subscriber base grew 35% year-on-year to 75m.
The growth also came despite a global service outage last October that left many BlackBerry users without email, internet and BlackBerry Messenger intermittently for three days.
Even though BlackBerry has lost ground to Apple's iPhone and devices running Google Android, the handsets remain popular in the pre-paid and youth markets.
BlackBerry co-founders Mike Lazaridis and Jim Balsillie stepped down this month as co-chief executives of RIM after the firm lost around $70bn (£45bn) in market value last year as its stock price tumbled by 75%.
The company's board "unanimously named" chief operating officer Thorsten Heins as RIM's new president and chief executive.
RIM saw its share of the US smartphone market dwindle to 16.6% in the final quarter of 2011, according to figures from comScore, lagging behind the around 50% held by Android devices and the 28.7% commanded by Apple's iPhone.
But RIM will introduce the new BlackBerry 7.1 update in the coming months, bringing new features such as BlackBerry Tag, an NFC technology that allows users to share contacts, photos and files by 'tapping' their devices together.
The Canadian firm has also announced PlayBook 2.0 for launch in February to boost its troubled range of tablet computers, which endured a massive price cut following dismal sales.
In an interview with The Daily Telegraph, BlackBerry UK managing director Stephen Bates said that the company had "learnt a lot" from the tough experience with the PlayBook.
He said that the tablet product had sold well over the Christmas period, and claimed that it was about extending the BlackBerry experience for customers.
"if you don't have a BlackBerry then it's not the tablet for you - if you've got an Apple you're more likely to buy an iPad, Android users are more likely to buy an Android-based tablet," he admitted.
At the end of the year, BlackBerry will launch its delayed BlackBerry 10 operating system, which will power the next generation of the company's smartphones.
"This new operating system is not about the short term, this is about us getting fit for the next 10-15 years," said Bates.
"Yes we want to be quicker with new capabilities; yes we want to add new things; yes I would love them to come faster - but the reality is that some of this stuff is hard."
Bates also backed Heins to lead RIM back to prosperity. He said: "There is no shortage of innovation at BlackBerry - we just have to crack this delivery and Thorsten is a great man for that."