Temasek Holdings filed an appeal this week with an Indonesian court to contest a ruling by the country’s business regulator that it breached local anti-monopoly laws, the state-linked investment firm said.

Indonesia’s business regulator, the Commission for Supervision of Business Competition (KPPU), said last month that Temasek acted illegally in its investments related to the country’s two largest cellular phone operators, Telkomsel and Indosat.

Temasek, which does not directly own stakes in the two Indonesian telcos, has said it is not guilty of breaking anti-monopoly laws and vowed to fight the KPPU ruling.