Nokia has developed more than one new model and is due to announce them at an event in New York in late September, said the sources familiar with the plan.
The sources would not elaborate on details such as specifications and price but said the new models will include a phablet, a common name for smartphones with screens over 5 inches. Technology blogs have also said that Nokia plans to launch a tablet device.
Nokia officials were not immediately available for comment.
A phablet would be the latest addition to Nokia's range of Lumia smartphones which use Microsoft's Windows Phone software.
The move comes as the Finnish mobile phone company, which has fallen behind Samsung and Apple in smartphones, has stepped up its pace of product launches in the past year in a bid to stem a decline in sales.