AT&T plans to start selling a Nokia smartphone with Microsoft Corp. software for half of what it charges for the iPhone, as the device’s makers seek to break Apple and Google’s dominance of the U.S. market. The Lumia 900, which runs on AT&T’s network using faster, so-called long-term-evolution technology, will start selling for $99.99 on April 8, the second-largest U.S. wireless carrier said Monday in a statement. The latest iPhone and newest handsets running Google’s Android software typically start at $199. Nokia is counting on Microsoft’s Windows Phone software to reignite sales in the U.S., where the iPhone and Android makers such as Samsung control 78 percent of the market. Microsoft is trying to increase its share of the mobile software market to expand beyond the slower-growing personal-computer market. Microsoft, based in Redmond, Washington, rose 1.4 percent to $32.46 at 11:34 a.m. New York time. Nokia, based in Espoo, Finland, advanced 0.4 percent at 3.99 euros in Helsinki trading. The Lumia 900 has a 4.3-inch screen and an 8-megapixel camera.