AT&T, Inc. (T) recently signed a multi-year purchase agreement with Corning Incorporated (GLW) . Per the deal, AT&T will leverage Corning’s industry-leading fiber, cable and connectivity solutions to accelerate fiber network expansion and deliver high-speed reliable Internet across the country. In addition, AT&T is also driving its network expansion initiatives through other channels, including a joint venture with BlackRock called Gigapower.The company recently marked broadband subscriber growth for the fi ...