Canadian miner First Quantum Minerals Ltd. headed for a one-week low after a ruling by Panama's Supreme Court cast uncertainty over a major copper mine it's developing in the central American country... the court ruled on Monday that Law 9 -- used to approve a mining concession contract between the state and Minera Petaquilla in February 1997 -- was unconstitutional... First Quantum said "the Supreme Court ruling only affects the enactment of Law 9, and does not affect the mining concession contract itself, which remains in effect, and therefore allows continuity of development of the Cobre Panama project," according to a statement... The company is in the process of obtaining and examining the ruling, and “is working with the appropriate parties to identify suitable legal remedies,” First Quantum said... La Prensa, one of Panama’s major newspapers, reported that the court indicated in its decision that country’s National Assembly accepted a contract that didn’t follow the correct legal process and therefore contravened the constitution.