At least four Communist China's hybrid petro and gas companies have strong links to China's military.

Beijing's largest offshore oil producer CNOOC Ltd. could be most at risk as the Pentagon’s listed it among the companiesare owned or controlled by Chinese military, according to Bloomberg Intelligence analyst Henik Fung. PetroChina Co. Ltd. and China Petroleum and Chemical Corp., also known as Sinopec, may also be under threat as the energy sector is crucial to China’s military, he said.

More Chinese companies could get delisted in the U.S. and the oil majors could come as the next wave, said Steven Leung, executive director at UOB Kay Hian in Hong Kong. At the same time, the impact of removing the telecom firms is probably minimal as they were thinly-traded in the U.S. and they haven’t raised much funds there, he added.

The NYSE said on Saturday, it would delist the telecom operators to comply with a U.S. executive order imposing restrictions on companies identified as affiliated with the Chinese military.

China Mobile Ltd., China Telecom Corp Ltd. and China Unicom Hong Kong Ltd. would all be suspended from trading between Jan. 7 and Jan. 11, and proceedings to delist them have started, the exchange said.

U.S. President Donald Trump signed an order in November barring American investments in Chinese firms owned or controlled by the military in a bid to pressure Beijing over what it views as abusive business practices. The order prohibited U.S. investors from buying and selling shares in a list of Chinese companies designated by the Pentagon as having military ties.