Moto Goldmines Ltd. (MGL.T) Monday said a takeover offer from Randgold Resources PLC (GOLD) is "potentially superior" to an earlier offer from Red Back Mining Inc. (RBI.T).

"Moto will now commence negotiations with Randgold concerning its offer," Moto said in a statement.

Randgold Thursday said it had teamed up with AngloGold Ashanti Ltd. (AU) in a bid for Moto which values the Congo-focused gold exploration firm at about 546 million Canadian dollars($488 million).

Perth, Australia-based Moto in June agreed to a C$513 million all-share acquisition by Red Back, another Africa-focused mining firm with operations in Ghana and Mauritania.

Red Back would have the right to match Randgold's offer if Moto and Randgold reach a definitive agreement, Moto said.

-By Jeffrey Sparshott, Dow Jones Newswires; +44 (0)207 842 9347; jeffrey.sparshott@dowjones.com