BEIJING -- Three of China's largest state-owned energy companies replaced their top leaders Friday, two with industry outsiders, in what is seen as a bid by Beijing to assert greater control as well as a possible prelude to a broad sector realignment. China Petrochemical -- better known as Sinopec Group -- China National Petroleum Corp. and State Grid Corp. of China all appointed new chairmen with immediate effect. Sinopec Group's new chairman, Zhang Yuzhuo, previously led top Chinese coal-mining company Shenhua Group and in 2017 became the head of a special economic zone in Tianjin.