The number of smartphone shipments exceeded 157 million in Q3 this year, with Samsung increasing its lead in terms of unit shipments.

That is the view of mobile analyst firm Juniper Research, who says during the third quarter the South Korean based company shipped a record 56.3 million smartphones.

The sales represents almost double the market share of its rival Apple, which sold 26.9 million.

Samsung’s flagship device, the Galaxy S3, played a key role according to Juniper, with estimated sales of 18 million during the quarter ending September 30.

With the festive season still to come however, and with a new and refreshed product line, including the iPhone 5, Apple is expected to better its sales in the fourth quarter.

RIM and Nokia struggle

Nokia’s Windows devices have yet to make a significant impact, with the Finnish company shipping just 6.3 million smart devices in the third quarter – a 63% fall compared to Q3 2011.

This was partly due to customers waiting to buy into the new Windows 8 platform due in Q4 according to Juniper.

RIM’s recent results – which run to a different financial schedule – hint at continuing problems for the Canadian firm with just 7.7 million quarterly smartphone shipments, with fellow competitors including HTC and Motorola continuing to fall short.