Rio said Glencore had contacted it about a potential merger in July, which it turned down in August, adding that there had been no further contact between the companies on a merger.

By 9.38 p.m. EDT on Monday, Glencore shares were trading up 3.9 percent at HK$42.80, while the benchmark Hang Seng index was down 0.3 percent. Rio shares were up 3.2 percent in Sydney trading.

(Reporting by Denny Thomas; Editing by Richard Pullin)