Microsoft has revamped the browser ballot screen as demanded by European Union antitrust regulators and may now get final approval as early as 15 December, according to a source familiar with the case.

As first reported by the Bloomberg news service, Microsoft modified the ballot screen after rivals demanded changes. Last month, Opera, Mozilla and Google, submitted change requests to the European Commission, asking that the order of the browsers be randomised and that the ballot be displayed in its own application, not in Internet Explorer.

The EU's antitrust case, which kicked off last January, had been sparked by complaints filed by Opera in December 2007 , when the Norwegian browser maker accused Microsoft of shielding IE from real competition by bundling it with Windows. To level the playing field, the commission wants Microsoft to let consumers decide which browser they use.

Previously, Microsoft had tweaked the ballot to gain the commission's preliminary approval in October. Microsoft first agreed to the ballot approach last July as a way to resolve the case.

According to the source, who asked not to be identified because the terms of the settlement have not been officially approved, the top five browsers - IE, Firefox, Chrome, Opera and Apple's Safari - will appear in random order each time the ballot is displayed.

Mozilla had been the most vocal about how the ballot would display choices. Last month, for example, Jenny Boriss, a Firefox user experience designer, denigrated the ballot's layout and said that it gave IE more than three times the space than rivals' browsers because the ballot would be displayed within Internet Explorer.

Hakon Wium Lie, Opera's chief technology officer, agreed with Mozilla that randomising the browsers on the ballot would be a better solution than Microsoft's original idea, which was to list them alphabetically by maker, a move that would put Apple's Safari in the preferred left-hand position. "Alphabetising would just lead to opportunistic naming," Lie said in early November. "We could call ourselves AAA Browser Maker and get the first spot."

Lie also supported other changes, including removing the ballot from the framework of IE - Microsoft's proposal would craft an HTML page to display the ballot, which would then appear inside its own browser - and assurances that Microsoft would disable any security warning when people picked a browser to download and install. "The general security warning that you get prior to a binary download should not appear," Lie said last month.

It's unclear what other changes, if any, have been made to the ballot as proposed in October.

The deal may be finalised as early as 15 December, when EU commissioners meet to vote on a number of issues, said the source. If the date is accurate, Microsoft would begin pushing the ballot to European users of Windows XP, Vista and Windows 7 in mid-February. The company's must release the ballot via Windows Update eight weeks after officials sign off.

When the ballot screen is approved and then delivered to PCs, users will be offered a choice of browsers only if they have set IE as the default Web application. New PCs sold in the EU will also include the ballot screen, which will appear the first time the owner tries to go on the Internet.