* More than 50 carriers are already testing new devices
* RIM shares close higher on Nasdaq and TSX
(Adds background, details, share price move)
TORONTO, Oct 31 (Reuters) - Research In Motion said on Wednesday it has begun carrier testing of its new line of BlackBerry 10 devices, a crucial step ahead of next year's launch of the make-or-break line of smartphones.
``In the last week, BlackBerry 10 achieved lab entry with more than 50 carriers, a key step in our preparedness for the launch of BlackBerry 10 in the first quarter of 2013,'' Chief Executive Thorsten Heins said in a brief statement.
RIM, which once commanded the lead in the smartphone market, has rapidly lost ground to Apple's iPhone and Samsung's line of Galaxy products, especially in North American and European markets, as customers abandon its aging BlackBerry devices.
Waterloo, Ontario-based RIM is trying to reinvent itself through the new smartphones that will run on the BlackBerry 10 operating system on which it has staked its future. It says the new devices offer a faster and smoother user interface and a better platform for the apps that are critical to a smartphone's success.
RIM, attempting to lure developers onto its platform, last month showed off the new devices to a large gathering of app creators in San Jose, California.
While the devices have so far been well received by the developer community, analysts say the test will be the reception from consumers in an ultra-competitive market dominated by the iPhone and devices that run on Google Inc's Android software.
Testing with carriers typically runs two to three months and lets telecom players test the compatibility of the new devices with their networks.
``This process will continue in the coming months as more carriers around the world formally evaluate the devices and our brand new software,'' said Heins.
``Our developer teams are continuing to generate momentum to bring a wealth of applications to BlackBerry 10, our enterprise teams have started to present BlackBerry 10 devices and services to our business customers, and our engineers are fully mobilized to ensure that BlackBerry 10 launches flawlessly in the first quarter of 2013.''
Shares of RIM closed 4.7 percent higher at $7.93, Wednesday on the Nasdaq. The Toronto-listed shares ended the day 3.7 percent higher at C$7.88.
(Reporting by Euan Rocha; Editing by Janet Guttsman and Leslie Adler)