SEOUL, South Korea — South Korean antitrust investigators questioned employees at Intel Corp.'s local subsidiary this week as part of an inquiry that began last year, a company spokesman said yesterday.

The Korean Fair Trade Commission investigators "made an unscheduled visit to our offices on Tuesday during normal business hours," said Chuck Mulloy, legal affairs spokesman for Intel in Santa Clara, Calif.

"This is part of an ongoing inquiry that we disclosed in June of 2005," Mulloy said. Mulloy said the visit to Intel Korea marked the first time regulators had arrived unannounced.

A Fair Trade Commission spokesman, speaking on condition his name not be used, confirmed officials investigated Intel this week, but said he couldn't provide details.

The spokesman added that he couldn't say when the investigation will end, but hinted it could take some time, citing the commission's earlier investigation into Microsoft Corp.

The FTC ruled in December, after a nearly four-year investigation, that Microsoft abused its market dominance in South Korea, fining the software giant $34 million and ordering it to offer alternative versions of Windows. Microsoft said it will fight the decision in court.

Yonhap news agency quoted an unidentified FTC official as saying the Intel probe was focused on whether the company abused its dominant position by pressuring computer makers to avoid using chips made by its rivals.

Intel, the world's largest chip maker, is facing numerous legal battles over how it maintains its market position. Intel has repeatedly denied it has broken any laws.