Nokia Oyj has filed an appeal with the regional court in Mannheim, Germany, in its legal battle with U.S. chipmaker Qualcomm Inc , Nokia said on Tuesday. The court last month dismissed the case in which Nokia is challenging Qualcomm patents regarding chips used in Nokia handsets.

The companies have been at legal loggerheads since they failed to renew a key technology licensing pact that expired on April 9.

If Nokia wins the case on appeal, Qualcomm would be prevented from enforcing its patents that have also been licensed by Texas Instruments.

Qualcomm has sued Nokia over GSM patents in the United States, Germany, France, Italy and China. None of the cases has reached a verdict or settlement.