HONG KONG—Internet company Tencent Holdings Ltd. of China is in talks with SoftBank Group Corp. to buy the Japanese telecommunications giant’s majority stake in Supercell Oy, the Finland-based maker of some of the world’s most popular mobile games, according to people briefed on the discussions.

Tencent’s talks with SoftBank are still at an early stage, according to the people, and it isn’t clear whether SoftBank is currently in talks with other parties.

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