Sixty percent of U.S. Fortune 500 companies are already testing or using the system to manage BlackBerry’s new line of devices, the company said on Wednesday, as U.S. carriers began to roll out its new keyboard-equipped Q10 smartphone. The Q10, which comes with the tiny physical keyboard that many BlackBerry fans admire, is the second device powered by the new BlackBerry 10 operating system. The touchscreen Z10 launched earlier this year. The U.S. market is crucial for Waterloo, Ontario-based BlackBerry as it seeks to win back market share ceded to Apple Inc’s iPhone, Samsung’s Galaxy smartphones and other devices powered by Google’s Android operating system. “This is a very exciting day for us, launching with all four major U.S. carriers,” BlackBerry Chief Operating Officer Kristian Tear said in an interview.