OREANDA-NEWS. September 20, 2013. PetroChina Co, embroiled in a government graft probe, says a report that more of its executives are being investigated by authorities is not true.

China Business News reported yesterday that five more executives at PetroChina or its parent China National Petroleum Corp had been summoned by authorities.

It said they included Wang Guoliang, a PetroChina director, and Sun Longde, a vice president.

But PetroChina denied the report, which had prompted it to suspend its shares from trading in Hong Kong and Shanghai early yesterday morning.

"After verification, the company has confirmed that such reports are not true," China's largest oil company said in a filing to the Hong Kong stock exchange. "Wang Guoliang and Sun Longde continue to perform their duties at the company as usual."

Wang was the former chief financial officer of PetroChina while Sun recently replaced Li Hualin as board secretary. Li resigned last month after being put under investigation.

The newspaper also said that Wu Mei, chief of CNPC's planning department, and two executives of a PetroChina subsidiary had been detained. PetroChina didn't mention the three officials in its statement.

The newspaper said it was unclear whether the executives were being investigated or just helping with an investigation.

The government previously announced that five former executives at PetroChina or CNPC were being investigated for "severe disciplinary violations."

They included Jiang Jiemin, the former chairman of PetroChina and CNPC.

Shanghai-based Wison Engineering Services Co, a key contractor for PetroChina, said last week that its founder and chairman, Hua Bangsong, was assisting authorities in the investigation.

Analysts have played down any significant impact on PetroChina's shares.

"The fundamentals of the business are likely to see very limited impact. However, the uncertainty and the potential for a lengthy legal process to unfold is likely to be a near-term overhang on the stock performance," according to a report by Morgan Stanley's Andy Meng.

PetroChina shares gained after trading resumed in the afternoon, closing up 1.3 percent in Hong Kong and 2 percent in Shanghai.