Customers shop at the new Microsoft store in Washington in this file picture.

Brussels - The European Union fined Microsoft 561 million euros (731 million dollars) Wednesday for breaching the terms of an antitrust deal, the bloc's executive announced.

The European Commission said the US computer giant had failed to offer Windows users a choice of internet browser, as it had agreed to do in 2009 for a five-year period.

In return for that initial agreement, the EU had dropped an antitrust case.

“Microsoft failed to roll out the browser choice screen with its Windows 7 Service Pack 1 from May 2011 until July 2012,” the commission found in its ruling.

This meant that about 15 million Windows users in the EU were only given the option of using Microsoft's Internet Explorer programme, the commission wrote, amounting to a suspected abuse of market dominance.

EU Competition Commissioner Joaquin Almunia said Microsoft's failure to comply with legally binding commitments was “a very serious infringement that must be sanctioned accordingly.”

In October, Microsoft apologized for its failure to comply with EU demands, citing a “technical error” as the cause and insisting that it had taken steps to address the problem.

The EU has now fined Microsoft a total of almost 2.2 billion euros, after the software giant was sanctioned on three previous occasions.

Wednesday's fine is far below the maximum 10 per cent of turnover that the EU's executive can fine in antitrust cases, which in Microsoft's case would have been around 7 billion euros.

This was the first time the commission had to fine a company for not complying with commitments made in return for the closing of an antitrust case, the bloc said. - Sapa-dpa