Microsoft has only recently begun delivering its so-called “choice screen” for browser selection to consumers in Europe, but it’s apparently already producing the hoped for effect, at least for one small browser maker.

Norway-based Opera Software announced Thursday that since Microsoft (NASDAQ: MSFT) began sending the choice screen out earlier this month, downloads of its Opera 10.50 browser in Europe have doubled.

“After the choice screen launch in early March, on average, more than half of the European downloads of Opera’s latest browser come directly from the choice screen,” Opera said in a statement.

Microsoft began preliminary testing of the choice screen in mid-February in the U.K., Belgium, and France, followed by the beginning of full-scale deployment of the choice screen in March.

The choice screen — which is sent out to users via Microsoft’s Windows Update — came about as the resolution to an antitrust complaint lodged against the software giant by Opera in December 2007.

In January 2009, the European Commission’s (EC) competition directorate informed Microsoft, in what’s called a “statement of objections,” that it was seriously considering taking action against the larger firm over Opera’s complaint.

The EC argued that Microsoft had misused its Windows dominance on the desktop to enable it to block competing browsers by bundling Internet Explorer with the operating system going back to 1996.

Microsoft, which had come out of an earlier confrontation with the EC much humbled and a couple of billion dollars poorer in 2007, decided not to fight the browser complaint.

It ultimately agreed to let users select from other competitors’ browsers as well as IE when Windows starts up the first time.

A Fairer Browser Selection Process?

In order to make such a selection system more fair, the top five browsers — IE, Mozilla Firefox, Apple Safari, Google Chrome, and Opera — are displayed in randomized order each time the so-called “choice screen” comes up.

The intent is that, if given an unbiased choice, users will be able to make better decisions of which browser to use. The random selection process may well dilute IE’s market share in Europe in the process.

So far, however, only Opera has signaled that it is making gains due to the advent of the choice screen.

Google, meanwhile, declined to comment.

“We generally don’t share download stats on that granular of a level,” a Google spokesperson said in an e-mail to InternetNews.com.

Calls and e-mails to Apple and Opera seeking comment were not returned by publication time and, similarly, a Mozilla representative could not be reached by press time.