MANILA - A government panel cleared 23 of 27 Philippine mines that were assessed for compliance with state regulations, a source familiar with the talks said, easing uncertainty about potential supply disruptions at the world's No. 2 nickel ore supplier.

The Mining Industry Coordinating Council reviewed all 27 mines that were ordered closed or suspended last year by former Environment and Natural Resources Secretary Regina Lopez. Lopez has since been replaced by Roy Cimatu, a former soldier.

Most of the mines that Lopez had ordered shut were able to continue operations after lodging appeals, but Lopez's black letter approach to environmental protection had raised concerns about the certainty of nickel ore supply among buyers, including top importer China.

The panel's findings, including the fate of the four mines that did not pass the review, are subject to a final decision by the office of President Rodrigo Duterte and the environment ministry, the source said on Thursday.

The 27 mines were rated based on a number of criteria including legal, technical, economic, social and environmental compliance, said the source, who declined to be identified as the decision is not yet public.

"Based on the rating, four failed to get a 'passing' mark," the source said, without naming the mines.

Members of the government panel are expected to announce their recommendations at a media briefing later in the day.

Mining is a deeply contentious issue in the resource-rich Southeast Asian country after past examples of environmental mismanagement.

Duterte, who warned miners to follow tighter environmental rules or shut down shortly after he took office in 2016, has so far upheld a ban on new open pit mines.

In April, Duterte told miners to reforest areas where they operate, warning he will revoke their permits if he doesn't see trees as tall as he is in six months.

After last year's crackdown the government was also looking at fresh curbs to limit any environmental harm caused by mineral extraction.

Reuters reported earlier that the government was planning to limit the amount of land that miners can develop at any one time to boost environmental rehabilitation, a move that miners say may cut output of nickel ore in last year's top supplier to biggest buyer China.

Indonesia has been the top nickel ore supplier so far this year after Jakarta relaxed an ore export policy.

(Reporting by Manolo Serapio Jr.; Editing by Joseph Radford and Richard Pullin)

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