BlackBerry maker Research In Motion said on Thursday it has added more than one million subscribers in Europe, the Middle East and Africa in less than three weeks.

The announcement, posted on Twitter, was a rare update on what had been a key operational metric until RIM stopped regularly disclosing the figure late last year.

RIM has struggled to compete with Apple's iPhone and a slew of devices using Google's Android operating system, most acutely in the United States, where its market share has been slipping for many months.

RIM charges mobile network operators a monthly fee per BlackBerry user for access to its own infrastructure, which compresses and encrypts data before pushing it out to devices.

The service revenue enables RIM to boast the second highest margins in the industry behind Apple.

RIM added more than 5 million new subscribers globally in the three months to late November, for a total of more than 55 million.

Its Nasdaq-listed shares were 3 percent higher at $28.56 by early afternoon. They have lost half their value since the start of the year.

(Reporting by Alastair Sharp; Editing by Jeffrey Hodgson)

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