In its decade-long battle to reverse a one-time record European Union antitrust fine, Intel has made some small progress: its appeal continues.

According to court documents, the European Court of Justice today referred Intel's case back to the lower General Court, which had denied the appeal in 2014.

The EU Commission fined Intel €1.06bn in 2009 for providing anti-competitive rebates to PC-makers Dell, HP and Lenovo to use its chips instead of those made by rival AMD, plus making payments to German retailer Media Saturn Holding to only offer computers with Intel inside.

After the ruling, Intel had tried to annul the decision or reduce the fine in General Court. One of its arguments was that the Commission was incorrectly applying its test for determining if the rebates and payments restricted competition; it claimed if the test was applied correctly, the Commission would have seen that they were fine.

The General Court ruled that there was nothing to change, so Intel bumped the appeal to the European Court of Justice.

The Advocate General released a non-binding opinion (PDF) that the General Court should get a fresh review in 2016.

In its ruling today, the European Court of Justice found that the General Court had missed a few things, including addressing Intel's criticisms of the test. The General Court had decided that it wasn't necessary to check if it was error-free and followed the rules, or check if Intel had done its own alternative calculations correctly.

"The review by the General Court, in the light of the arguments put forward by Intel, of whether the rebates at issue are capable of restricting competition, involves the examination of factual and economic evidence which it is for that Court to carry out," the European Court of Justice ruling states.

The court did reject Intel's arguments that the Commission had mishandled interview procedure and mischaracterised its exclusivity rebates with HP and Lenovo, but did not rule on other parts of the appeal. ®