A conclusion to the six-year-long European antitrust case against Microsoft is imminent, a European Commission spokeswoman said yesterday.

"We are concluding the case," said Commission competition spokeswoman Amelia Torres.

Commission antitrust officials have drafted a final ruling in the case. The ruling may follow the line the Commission took last August when it issued Microsoft with a statement of objections. Microsoft was accused of abusing its dominant position in the software market by obstructing rivals' programs from working with the ubiquitous Microsoft Windows operating systems.

The Commission also accused the company of shutting out competitors to its Media Player audio-visual software by bundling Media Player into the computer code of Windows.

The Commission hosted a hearing in November at which Microsoft's rivals were invited to demonstrate how the software giant was distorting the markets they operate in. According to people present at the closed-door hearing, the Commission's misgivings about the way Microsoft competes were confirmed in the presentations.

Microsoft also gave its arguments at the hearing, but the real negotiations with the regulators didn't start until after it finished.

Negotiations in a case of this magnitude could continue "almost to the last day," said one person close to the Commission who asked not to be named.

"They may well continue beyond the ruling," he said, adding that it may be to the Commission's advantage to negotiate a settlement during the near certain appeal that would follow a negative ruling.

"They would be negotiating from a stronger position with a ruling behind them," he added.

The draft ruling was circulated to other departments within the Commission last week, according to one of the people close to the Commission.

The inter-departmental consultation usually takes around a month. Next the ruling would be circulated among national competition regulators from the 15 member states of the Union.

Competition commissioner Mario Monti's team will decide on the size of fine to impose on Microsoft a week before a final vote on the ruling by the 20 commissioners. People following the case said they expect it to conclude in March or April.

"As far as the competition department is concerned the ruling is final," said another anonymous source. Other parts of the Commission can comment but they don't usually change much to an antitrust ruling, he added.

Microsoft said on Monday that it is still negotiating with European Union regulators. "We are engaged actively and constructively with the European Commission," said a spokesman.