BlackBerry said it's also working with its other carrier partners to give its customers options should they want to switch to another carrier.
Chen said in a statement that the company hopes to work with T-Mobile again when their business strategies align.
The BlackBerry, pioneered in 1999, had been the dominant smartphone for on-the-go business people and other consumers before the iPhone debuted in 2007 and showed that phones can handle much more than email and phone calls. The BlackBerry has also been hurt by competition from Android-based rivals.
On Friday the company reported mixed fourth-quarter results as its adjusted loss was better than expected, but revenue - which dropped below $1 billion for the first time since late 2007 - fell short of analysts' expectations.
BlackBerry is transitioning its business from a smartphone company to a software business under Chen, who is deemphasizing the hardware business after last year's launch of the BlackBerry 10 failed to spark a turnaround.
Chen, who is credited with turning around Sybase, a data company that was sold to SAP in 2010, is putting more emphasis on BlackBerry's mobile device management business, a collection of software that allows IT departments to manage different devices connected to their corporate networks. He is also emphasizing BlackBerry's popular BlackBerry Messenger application that is now also available on Apple and Android devices. And he is trying to highlight Blackberry's embedded QNX software systems, which are used in-vehicle infotainment systems and industrial machines.
BlackBerry's stock dipped 2 cents to $8.08 in premarket trading Wednesday about three hours ahead of the market open.
