The European Commission has taken another shot at software giant Microsoft, by saying that the US technology company could be breaking the law by packaging its Internet Explorer web browser with Windows.

In what it is calling a "preliminary" view on a complaint by one of Microsoft's rivals, the Commission said it believes that the company "distorts competition on the merits between competing web browsers" by bundling IE with every copy of Windows.

In a statement, officials said that there were a number of possible problems with Microsoft's actions.

"The Commission is concerned that through the tying, Microsoft shields Internet Explorer from head-to-head competition with other browers, which is detrimental to the pace of product innovation and to the quality of products which consumers ultimately obtain," it said.

The complaint, made in 2007 by Norwegian web browser company Opera, is essentially an extension of the landmark case in the 1990s that saw Microsoft go up against the US government over allegations of anti-competitive behaviour.

In 1998, the US government tried Microsoft over accusations that it unfairly maintained its monopoly, ending with that the company "will use its prodigious market power and immense profits to harm any firm… that could intensify competition".

Although the US Department of Justice initially sought to split Microsoft in two, an intervention by President George Bush culminated in a settlement in 2001 – although thanks to a torturous appeals process, the agreement was not finally settled until 2004.

But commission officials said that the punishments put in place by Washington lawyers did not affect the legal standing of Windows or Internet Explorer in Europe.

The Seattle-based software company responded to the Commission's latest statement by saying that it is studying the documents and has two months to respond.

"We are committed to conducting our business in full compliance with European law," it said in a statement.

Although the company gave recognition to the statement of objection, it did not address the allegations themselves or state whether it would request a hearing.

The announcement is just the latest episode in a long and bruising conflict between European officials and the American hi-tech giant.

Last year, the EU fined Microsoft a record £680m for charging rivals "unreasonable" prices to access parts of its software – adding to other fines and levies totalling more than £1.5bn over the past four years.