Intel said it is being investigated for its business practices by the US Federal Trade Commission. Intel, the world's largest chip maker, said in a statement that it would co-operate fully with the commission in its investigation, thought to be into allegations of anti-trust activities.

The company, which has its European headquarters at Leixlip, Co Kildare, said a similar investigation in 1993 was closed when the commission concluded no further action was warranted.

The Federal Trade Commission declined to comment.

"As a rule, we don't confirm nor deny if we are conducting an investigation," an FTC official said in Washington.

Intel holds about 85 per cent of the market share for microprocessors in personal computers.

The Wall Street Journal reported that the FTC had asked computer companies, mostly Intel clients, for information about Intel's practices.

The Journal said the FTC was trying to determine whether Intel violated the law "by acting to monopolise, attempt to monopolise or otherwise restrict price or nonprice competition in the development or sale of microprocessors or other computer components."

The Journal also said the FTC wanted to determine if Intel was using its position to gain an unfair advantage in other sectors, such as defence technology. Intel is developing chips for Lockheed Martin for three-dimensional graphics.