The European Commission found leading computer chipmaker Intel guilty Wednesday of violating European anti-trust rules and ordered that it pay a fine of 1.06 billion euros. It is the largest fine the commission has ever imposed, said Neelie Kroes, the European commissioner for competition. Intel has said it plans to appeal the decision.

The commission found Intel abused its dominant market position in the market for computer chips known as the x86 computer processing unit (CPU), Kroes said. The abuse lasted more than five years, she said. Intel held a 70 percent share of the market during the period of the violations, she said.

"That Intel had such a large market share is not a problem in itself," Kroes said. "What is a problem is that Intel abused its dominant position. Specifically, Intel used illegal anti-competitive practices to exclude essentially its only competitor, and that reduced consumer choice -- and the whole story is about consumers."

The EC says Intel has systematically given PC makers and stores rebates to keep computers with AMD chips off the shelves. AMD (another American company and Intel's only competitor) first raised the red flag in 2000.