Environmental authorities in a city in eastern China have hit petrochemical giant Sinopec with a penalty reported to be 90,000 yuan ($14,670) for causing air pollution.

The rare move sets a good example in regional governments' battle against large State-owned polluters, experts said.

The Environment Protection Bureau of Anqing, Anhui province, made the decision after a branch of Sinopec, Asia's largest refiner, was found late last month to have discharged excessive amounts of polluting materials in the city of 6.2 million people.

An official with the bureau's publicity department told China Daily on Thursday that the environmental authorities are still dealing with the matter, and that the procedure involving a fine usually takes about three months.

"Sinopec breached the law, so we have the right to punish it," said the official, who declined to be identified.

The official also declined to reveal the amount of the penalty that the company received, saying that the procedure has not yet been completed.

A report by the 21st Century Business Herald put the figure at 90,000 yuan, which is viewed to be too small for a company that reported around 2.5 trillion yuan in revenue last year.

Experts said the penalty - even if the small figure is accurate - hit the headlines because it marks a victory for local law enforcers in their battle with mammoth State-owned companies, which can have administrative rankings even higher than those of regional governments.

This makes punishing them difficult, even though regional environment authorities are in theory empowered to supervise branches of State-owned companies, according to Ma Jun, director of the Institute of Public and Environmental Affairs.

One of the systemic problems in China's environmental protection efforts is that relevant authorities are not powerful enough and will always give in under administrative orders, he said.

In the Anqing case, regional authorities had remained inactive though residents had been filing complaints about the odor from Sinopec's refinery, which is closer to urban areas compared with its other refining plants across the country.

The oil refinery has been a vital part of industry in Anqing, and Wang Biao, general manager of Sinopec's Anqing subsidiary, also serves as a standing committee member of Anqing's Party committee.

Yu Fawen, secretary-general of the China Ecological Economics Society, said that the Anqing environmental authority had sent a "very positive signal" to other regional environment authorities.

"Although the penalty may be not very big, the punishment itself is of great significance. Its importance as a precedent is far bigger than the real impact it imposes on Sinopec," said Yu, who is also a researcher at the Chinese Academy of Social Sciences.

As for how much a polluting company should be fined, Yu said law enforcers can evaluate the levels of negative impact the company imposes on a region's ecology and the potential influences on its residents' health.

wangzhenghua@chinadaily.com.cn