Nokia's E7 phone will make its delayed debut this week, as the world's largest phone maker by volume tries to recover ground lost to Apple and Google in the smartphone market.

Nokia had postponed the rollout of the top-of-the-range E7 in December "to ensure the best possible user experience".   

The E7 is similar to its N8 model but has a full slideout keyboard. The N8 was also delayed and, after launch, Nokia admitted some of the phones had power problems.

The N8 and E7 are flagship models for the new version of Nokia's Symbian software.  

Nokia said they had already started deliveries of the E7 and it would go on sale from this week.

 A weak offering of smartphones and software problems were seen as the main reasons for Nokia replacing chief executive Olli-Pekka Kallasvuo with Stephen Elop from Microsoft last September.  - Reuters