The Korea Resources Corporation (KORES) has joined hands with Korean mining company LS-Nikko Copper to invest W1 trillion in a five-year project to develop a major copper mine in Panama (US$1=W1,198).

KORES on Thursday said it signed a contract with Inmet Mining Corporation of Canada for an option to acquire a 20-percent stake in the Petaquilla copper mine in the Central American country.

According to KORES, Petaquilla contains an estimated 1 billion tons of copper. KORES and LS-Nikko will invest W185 billion by next year to verify the exact size of the copper deposits.

If they choose to exercise their rights to the stake, they will pay W840 billion, or 20-percent of the mine's estimated development costs of W4.2 trillion.