Microsoft has agreed a deal to buy Nokia's mobile phone business for 5.4bn euros ($7.2bn; £4.6bn).

The purchase is due to be completed in early 2014, when about 32,000 Nokia employees will transfer to Microsoft.

While Nokia has struggled against competition from Samsung and Apple, Microsoft has been criticised for being slow into the mobile market.

Microsoft chief executive Steve Ballmer told BBC technology correspondent Rory Cellan-Jones the deal was "a big, bold step forward"