The head of the US Justice Department anti-trust division praised his European Commission counterparts on Monday - but not their approach to the Microsoft Corp case.
The European Commission ruled in March that Microsoft violated European antitrust law, fined it 497 million euros ($612.3 million) and ordered it to change the way it does business. The company plans to appeal that ruling this week.
R. Hewitt Pate, head of the Justice Department antitrust division, told a meeting of antitrust experts that Competition Commissioner Mario Monti's work is vital and will be remembered for decades, but Europe and America approached Microsoft differently.
"We have a continued potential for divergence," Pate said, speaking of Microsoft and some other cases.
Pate was careful to avoid criticism of Monti or any of his tactics - the two men said they had talked on the phone often while Monti was deciding Microsoft - but said they were separated by differing approaches to antitrust.
He said antitrust enforcers may want to be aggressive against monopolists but must avoid "rules whose applications to the general run of cases might have unwanted effects."
A few minutes later, Monti said that "where dominant companies can use their market power to win on the market for reasons that are not related to their products, prices or qualities then that is where we may consider intervening." He said competition must be on the merits of products.
Pate attributed the differences to variance in European-US legal principles, but some experts say the approach of the Bush administration itself represents a divergence from the approach of the Clinton administration to Microsoft.
The Clinton administration aggressively pursued the Microsoft case, refused to settle and won in the court of appeals, which narrowed the scope of the case. Pate's predecessor in the Bush administration made an agreement with Microsoft on remedies, rather than imposing them.