BlackBerry announced today it will end its licensing agreement with T-Mobile when it expires on April 25th, meaning the fourth-largest carrier in the United States will soon no longer be able to sell BlackBerry products. In a press release, John Chen, BlackBerrys CEO, said although the two companies had a positive relationship for many years, their strategies were regretfully, at this time […] not complementary. In February, T-Mobile sent out promotional material to customers that offered discounts on the iPhone when upgrading from BlackBerry devices. Chen responded with a blog post, in which he said he was outraged by the inappropriate and ill-conceived marketing promotion. T-Mobile responded by offering $250 to customers wanting to upgrade from an older model to a newer BlackBerry, but undercut the placating gesture somewhat by also offering its BlackBerry users $200 should they switch to another manufacturers products: a deal that saw 94 percent of T-Mobile customers with BlackBerry phones switch to a different phone maker.