The rights plan, which comes into force immediately, will ensure that all shareholders are treated fairly in connection with any takeover bid, First Quantum said.

State-backed Jiangxi Copper said in a regulatory filing last month that it would buy Cupric Holdings Ltd from Pangaea Investment Management Ltd. Cupric held around 18% of First Quantum's issued share capital as of Dec. 9.

First Quantum's rights plan is subject to ratification by shareholders within six months of its adoption.

(Reporting by Arundhati Sarkar in Bengaluru; Editing by Maju Samuel)