The head of Microsoft Corp.'s Japan unit acknowledged Tuesday that the U.S. software giant's battle with Japanese antimonopoly authorities over a controversial licensing clause has hurt its corporate image here.

But President and Chief Executive Michael Rawding said the company will continue to oppose a Fair Trade Commission ruling last month ordering Microsoft to retroactively remove the clause from its licensing agreements.

The clause prevents companies from suing Microsoft over patent and copyright infringement, in which elements of manufacturers' own software technology might end up in the Windows operating system.

Rawding said legal wrangling could last as long as two years. Commission officials also say the battle could be a long one.

"It's never a good thing to be involved in this sort of activity," Rawding said when asked if the dispute has hurt Microsoft's image in Japan. "It was appropriately reported by the media as to the issues in the case, and why the case is not necessarily cut and dry."

Microsoft dropped the clause earlier this year in its contracts, but it has repeatedly said the wording is lawful.