The smallest and lightest-ever BlackBerry mobile phone, the Bold 9700, officially goes on sale today.

Measuring just 122g, the Bold 9700 is 14g lighter than the previous edition of the handset, the Bold 9000, and is nearly 1mm thinner.

However, it still retains the core features of BlackBerry mobiles, including a QWERTY keyboard and push email, which have made the devices such a hit with business users.

Phil Lander, commercial director of BlackBerry manufacturer Research in Motion (RIM), said that the changes to the handset had been made following extensive customer surveys.

He said: "The feedback was that it's a phenomenal device but can you make it a bit smaller to fit in your pocket or handbag. It's the slimmest, sleekest smart phone from BlackBerry to date."

Other notable differences from the 9000 include a trackpad navigation system in place of a trackball and an upgraded 3.2 megapixel camera.

The Bold 9700 has been available to pre-order from Top 10 Mobile Phones for the last week.