* Review follows closure, suspension orders in 2017 crackdown
* Findings subject to final decision by Duterte, ministry
* Philippines is the world's No.2 nickel ore supplier (Updates with official announcement, quotes)
MANILA, June 21 (Reuters) - A government panel cleared 23 of 27 Philippine mines that were reviewed for compliance with state regulations, reducing uncertainty about potential supply disruptions at the world's No. 2 nickel ore supplier.
Confirming an earlier Reuters report, the Mining Industry Coordinating Council found four mines did not meet the criteria set by the government. But officials also said the panel's findings are still subject to changes.
The panel 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 Lopez has since been replaced by Roy Cimatu, a former soldier.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 Lopez had ordered shut were able to continue operations after lodging appeals, but her uncompromising approach to environmental protection had raised concerns about the certainty of nickel ore supply among buyers, including top importer China.
"Four out of 27 failed to meet the criteria," Finance Undersecretary Bayani Agabin told a media briefing. Of the four that failed the review, three are nickel mines and one is a chromite producer.
The mines were rated based on a number of criteria including legal, technical, economic, social and environmental compliance, a source familiar with the discussions earlier told Reuters.
The panel's findings can still change, said Danilo Uykieng, assistant director at the Mines and Geosciences Bureau. The economic aspect of the review is not fully covered, he said, and the number of those who failed could be increased or decreased.
All findings are also subject to a final decision by the office of President Rodrigo Duterte and the environment ministry.
The panel meets again in the last week of July, Agabin said.
Mining is a deeply contentious issue in the resource-rich Southeast Asian country after past examples of environmental mismanagement.
There are 50 operating mines in the Philippines, 30 of which extract nickel ore.
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, a policy launched by Lopez.
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 Philippine 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 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, Richard Pullin and Tom Hogue)