Lafarge will buy out the remaining 45% interest held by Socam Development in Lafarge Shui On Cement, subject to the completion of its planned merger with Holcim. It will pay €294m (£214m).
Lafarge Shui On Cement would become a wholly-owned subsidiary of LafargeHolcim following completion of the merger project and the purchase.
Lafarge Shui On Cement has total cement production capacity of 32 million tonnes. It operates in the South West China provinces of Yunnan, Sichuan, Guizhou and Chongqing.
The transaction is also subject to approval of Socam shareholders.