Temasek Holdings filed an appeal against an order to divest its stake in one of Indonesia's two largest mobile phone operators, the Straits Times reported on Wednesday.
The appeal was filed with the District Court of Central Jakarta and a ruling is expected within 30 days, the newspaper said, quoting Temasek spokeswoman Myrna Thomas.
Temasek officials were not immediately available for comment.
Indonesia's competition watchdog KPPU ruled last month that Temasek had violated the country's anti-monopoly laws and ordered the Singapore company to divest its stake in either Telkomsel or Indosat Tbk PT.
KPPU also ordered Telkomsel to cut its mobile phone charges.
Temasek disputed the findings, noting its indirect stake in Telkomsel is smaller than the Indonesian government's.
The Singapore company also said its units had applied and obtained approval from Indonesian regulators, including KPPU, when the investments were made about five years ago.
Singapore Telecommunications, in which Temasek holds a 56 percent stake, has a 35 percent slice of Telekomsel. Telkom Indonesia, which owns the remaining 65 percent stake, is majority owned by the Indonesian government.
Asia Mobile Holdings, which is 75 per cent owned by Temasek unit Singapore Technologies Telemedia and 25 per cent by Qatar Telecom, hold about 40 per cent of Indosat's shares.