A patent battle between Microsoft and Guatemalan inventor Carlos Armando Amado looks to set to continue as a federal court reverse the decision made by a lower court.

Amado sued Microsoft in 2003, alleging that several versions of Office Suite infringed his patent for a software program, which links databases and spreadsheets.

A jury in the US ruled in favour of Amado and awarded him 4 cents per infringing unit.

The case was appealed and then remanded to a district court, which tripled the damage award.

But now a federal court which hears patent appeals has told the lower court to reconsider these damages.

The US Court of Appeals for the Federal Circuit rejected the damages award of 12 cents per copy because the lower court failed to explain how it calculated the award, reports Reuters.

"Because the district court failed to adequately explain the basis for its award of $0.12 per infringing unit sold during the stay of the permanent injunction, however, and because recent Supreme Court action may affect post-verdict damages, we vacate in part and remand", the appeals court said.

The appeals court, however, did not recommend how much the award should be, saying that "logically" the award should "fall somewhere between" 4 cents (which is what Microsoft says it should be) and $2 per copy (which was Amado's original claim).

The new ruling also said that the US District Court for the Central District of California "did not abuse its discretion" by dissolving its permanent injunction barring Microsoft from using the softwar, adds Reuters.