Online retail giant Amazon saw its share price tumble after releasing its fourth quarter results, despite posting profits of $239m.

Profits for the quarter jumped from $97m for the same quarter in 2012.

The US firm's figures also showed a 20% increase in sales of $25.59 billion for the quarter to the end of December, up from $21.27 billion for the same time the previous year.

But the results missed expectations, and with modest revenue forecast for the current quarter, shares dipped 10% in after-hours trading.

The company is predicting net sales of between $18.2 billion and $19.9 billion in the first three months of 2014.

Amazon saw a increase in sales for the whole of 2013 of 22% to $74.45 billion, up from $61.09 billion in 2012.

Despite the share blip, Jeff Bezos, Amazon's founder and chief executive, said now was "a good time to be an Amazon customer", highlighting increased support for Kindle customers and the new service of Sunday deliveries.

Amazon's UK arm saw its biggest ever day of sales on December 2, the so-called "cyber Monday", when 4.1 million items were ordered, at a rate of 47 items a second.

That eclipsed the previous busiest day set just four days earlier, on November 29, when 4 million items were ordered.

Amazon to move to bigger offices in Dublin

Amazon has announced that it is to move its Dublin Development Centre to a new 69,000 sq ft office space in Dublin 4.

The company currently employs around 450 people here. But  the new three floor premises at Burlington Plaza can accommodate up to 600 staff.

The first phase of the move is expected to take place in April, when 100 existing employees will transfer. The remainder will move by June. 

Amazon opened its Dublin Development Centre in 2005, where a team of engineers and developers provide support to its websites and web based services.

The centre also hosts support and technical assistance teams for a range of other Amazon products.

Roles at the centre are in the areas of engineering, software development and technical management.

Jeff Caselden, the Managing Director of the centre, said Amazon had created hundreds of jobs here over nine years, and it had found the talent needed to continue its growth. 

Amazon's growth in Ireland has been supported by the Department of Jobs, Enterprise and Innovation through IDA Ireland. The company's decision to move to bigger premises has been welcomed by both Mr Bruton and head of the IDA Barry O'Leary.