Microsoft will only have AT&T to lean on in the US when it comes to its new flagship smartphones.<br />Verizon Wireless, T-Mobile and Sprint have no intention to sell either the Lumia 950 or Lumia 950 XL, according to people familiar with the carriers' plans.<br />AT&T said on Tuesday that it would offer the Lumia 950, but hasn't commented on the Lumia 950 XL.<br />The Lumia 950 and Lumia 950 XL represent the first flagship Windows-powered smartphones in more than a year and a half, as well as the first marquee products under Microsoft, which acquired Nokia's devices business last year.<br />The phones are the Redmond, Washington, software giant's latest attempt to keep Windows relevant in the smartphone world.