Indian pharma major Ranbaxy Laboratories Ltd has won a case against Pfizer Inc. on a process patent for the cholesterol drug atorvastatin in Norway, the company stated Thursday.

"The Norwegian court sided with Ranbaxy by finding non-infringement of one key Pfizer Norwegian Process Patent," the company statement said.

Ranbaxy's atorvastatin product was, however, "found to infringe another Pfizer Norwegian patent covering a particular intermediate compound", the company said, announcing plans to appeal immediately to the Norwegian Court of Appeals.

The cholesterol-lowering drug is marketed by Pfizer as Lipitor.

Two other Lipitor patents were at issue but were not ruled upon by the Court.

A leading generic drug maker, Ranbaxy plans to file an invalidity action in the Oslo City Court against the intermediate patent.

Ranbaxy had made no claim for invalidity against this intermediate patent earlier.