Norwegian browser maker Opera urged European Union antitrust regulators on Monday not to rush to close its antitrust case against Microsoft before ensuring a level playing field among browsers.

European Competition Commissioner Neelie Kroes said in a newspaper interview last week that she was keen to reach a deal with Microsoft before her term ends this year. A settlement would end the company's decade-long dispute with the European Commission. We are slightly concerned about perhaps a premature settlement in this case, Opera's Chief Technology Officer Hakon Wium Lie told Reuters in an interview.

We are also eager to close the case but we want to make sure the settlement is effective. We think the current solution on the table will not be an effective settlement, he said. We think they need to hear and listen to our comments.

Opera in December 2007 complained to the Commission about Microsoft's tying of its Internet Explorer browser to its Windows operating system, triggering formal charges from the Commission against Microsoft in January this year.

The EU competition watchdog is now reviewing feedback from Microsoft's rivals and other interested parties on the U.S. software company's proposal to install a ballot screen that would give users the chance to choose its competitors' Web browsers.

Wium Lie said other browser makers also backed Opera on the issue.

Google and Mozilla are in line with this. Other ECIS members are also in line, he said. The Mozilla Foundation operates the Firefox browser.

Members of industry group ECIS include IBM, Nokia, Oracle Corp and Sun Microsystems.

We think the ballot screen is a good starting point for discussion but the way they thought of implementing it, we think it is not an effective remedy, Wium Lie said.

A confidential Commission questionnaire obtained by Reuters last week showed regulators were concerned about whether users would understand they were being offered a choice of browsers and whether they would actually use the ballot screen.

Microsoft's proposed ballot screen could be perceived by some users as spam, said Wium Lie.

What we would like is to have a native ballot screen which looks and feels like other Windows software updates and not running inside the browser. That is what Windows users are used to getting.

He also said computer makers could remove the ballot screen under Microsoft's proposed implementation -- before consumers get to see the browser option.

The Commission has to date slapped a total 1.68 billion euros in fines on Microsoft for infringing EU antitrust rules.

(Reporting by Foo Yun Chee, editing by Jason Neely)

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