Intel's anticompetitive conduct occurred between October 2002 and December 2007, the commission found.
The company had allegedly done this by trying to force AMD out of the micro-processor market. The court in Wednesday's decision, however, didn't rule on three other parts of Intel's appeal, including the amount of the fine and the EU's characterization of some of the rebates. It's not clear yet if the ECJ's decision will have any impact on this case, or indeed any cases going forward, but it nonetheless represents a victory for American technology companies which claim they are unfairly targeted by European antitrust regulators.
Intel appealed, but the fine was upheld in 2014. "The court sent the case back to the General Court for reassessment in light of its holding".
Those payments significantly diminished the ability of companies such as AMD to compete on the merits of their own chips, reducing their incentive to innovate and restricting consumer choice.
However, Intel has challenged the way that the Commission carried out the "as efficient competitor" test, and the conclusions it reached as a result. Google has said it is considering an appeal. The General Court's failure to do so was an error in law, it said.
"The lengthy appeals process took a major step in Intel's favor today, with the ruling that the General Court should have considered whether Intel's pricing practices were capable of harming competition", wrote Steve Rogers, Intel executive vice president and general counsel, in a blog post on the company's website. The court turned it down, arguing that the exclusivity rebates were by nature "incompatible with the objective of undistorted competition within the common market".
On Wednesday, the CJEU said the General Court had failed to properly examine the issue of whether the rebates did actually stifle competition.
John Schmidt, a competition lawyer at Shepherd & Wedderburn, says all that was typically needed to prove anti-competitive behaviour was to link discounts to exclusivity, but this approach brushed aside some of the tricky details of economic markets. The EU said that it is now up to the General Court to review the commission's decision.
"This is a setback for the Commission as it will be more closely scrutinized by the courts in the future".