The stock prices of China's top 3 State-owned oil giants underwent fluctuation on Tuesday, after new heads were named at the three companies on Monday.

The share prices of all three companies dropped after a brief rise in the morning. The China National Petroleum Corporation (CNPC) saw a 3.63 percent share price slump while the share prices of the Sinopec Group and the China National Offshore Oil Corporation (CNOOC) slumped 2.94 percent and 1.06 percent respectively, compared to the closing prices on Monday.

The stock fluctuation came after three new chairmen, Wang Yupu, Wang Yilin and Yang Hua, were named, respectively, for Sinopec Group, CNPC and CNOOC.

The change of leaders comes at a time when the sector is facing a series of challenges including industrial reform, low global oil prices and the government's anti-corruption campaign.

The change also added credibility to merger rumors regarding the three companies, analysts said, though the CNPC denied the rumor in an official announcement published Friday.

"Leadership changes should have a limited influence on the companies' stock performance," said Lü Bin, an analyst at commodity and energy researcher Sublime China Information Group. 

"It shows an inclination toward a merger, and if that really happens, the oil stocks would benefit significantly," Lü told the Global Times on Tuesday.

Han Jingyuan, an oil analyst at 315.com, an O2O e-commerce platform for bulk commodity, told the Global Times on Tuesday that a partial merger is more likely to take place. "A merger in the three companies' overseas sectors would boost their global competitiveness, but their domestic business is unlikely to be combined since market competition is needed in China."

Han also said the chairmen changes could reduce corruption, leading to better development of the three firms.

The former general manager of Sinopec Group Wang Tianpu was put under investigation last week for suspected "serious law and discipline violations," while the former general manager of CNPC Liao Yongyuan and CNOOC former deputy general manager Wu Zhenfang were investigated in March and April, according to the Communist Party of China Central Commission for Discipline Inspection.

As China's oil industry faces a bottleneck because of a slump in global crude oil price, the financial performance of all three companies has declined, according to first-quarter  financial reports released by the three.

The first-quarter revenue of Sinopec slumped 25.4 percent year-on-year. CNPC saw a 82 percent net profit year-on-year slump in the first three months of 2015, while the sales revenue of oil and gas at CNOOC dropped 39.9 percent compared to the corresponding period last year.