Finnish handset maker is expected to announce the Symbian Belle OS at the Nokia World event that is scheduled to take place on October 26 and 27 in London.

Various reports suggest that Symbian Belle OS, which is the next and may be the last upgrade to Symbian, will make debut on the Nokia 603 smartphone.

The Nokia 603 smartphone will come equipped with a touchscreen with 360 by 640 pixel resolution, a 5-megapixel full focus photo snapper, a 1 GHz processor, HSPA+, Wi-Fi and Bluetooth

The imminent smartphone will also have support for microSIM cards and NFC technology that will allow users to make payment for purchases via the phone.

The Symbian Belle OS will allow users to resize the home screen widgets and customize the overall feel of the software. It will also be possible to scroll the main menu, and toss between live images of open applications.

Belle software is widely expected to be the last upgrade to Nokia's Symbian as the Finnish handset maker has partnered with Microsoft to base its future handsets on Windows Phone OS.