Disini was referring to a case filed by environmental groups before the court in 1997 questioning the legality of the Mining Act.

"They should come out with the decision now," Disini said, adding that the legal challenge to the law liberalising foreign ownership on mining projects clouded prospects in the industry.

He said that since the approval of the Mining Act in 1995, only three firms have been given permits known as foreign technical assistance agreements (FTAAs) by the government to explore up to 81,000 hectares of prospective mining areas in the country.

At least 80 foreign companies had previously sought such permits, officials have said.

Officials and industry executives have said slow approval of mining permits to foreign companies had dampened interest of foreign firms.

"We have to keep waving the flag to attract investors," Disini said, adding the industry needed foreign capital to either reopen or explore new mines.

The Philippines used to be one of the top 10 world producers of copper, gold, nickel and chromite in the 1980s.

Officials at the state-agency Mines ang Geosciences Bureau said only three gold and copper mines remain in operation in the country as well as four nickel mines and two chromite mines.

Some 50 to 60 mining firms used to operate in the Philippines from 1970 to 1980, operating dozens of mines, including copper and gold mines.

Mineral exports accounted for about 20 percent of the country's total, said Patrick Caoile, president of the Philippine Mine Safety and Environment Association.