When former Nokia customer Angelo Amato went to get a new smartphone at an AT&T Inc. store in Manhattan last week, he never got a chance to even see the Finnish company's models. The shop didn't have any of Nokia's nine-month-old Lumia line and the salesman didn't mention it as an option.

"I would consider a Nokia again, but I've never heard of Lumia," said Amato, 41, who owns an Android phone made by HTC Corp.

Amato's experience underscores what Nokia's smartphone chief Jo Harlow says is the former market leader's biggest challenge to resurrect the business and reverse market share losses to Apple's iPhone and devices running Google's Android. Last quarter, Nokia sold 600,000 handsets in North America, little changed from the previous period even after introducing the flagship Lumia 900 in April. Apple sold 5.9 million iPhones in the U.S. in the quarter, according to Strategy Analytics.

Stephen Elop, former Microsoft executive who was brought in to revive Espoo, Finland-based Nokia, is betting advertising by Microsoft to push new Windows 8 will help Lumia.

Nokia plans to announce Windows Phone 8-based handsets as early as next month at its Nokia World event -- ahead of an expected Sept. 12 unveiling of the next version of the iPhone -- and have them for sale before the year-end holiday shopping season, said a person with knowledge of the matter, asking not to be identified because the plan isn't public.