The Chinese government said a two-month investigation into possible conflicts of interest in the coal industry found that 4,578 government officials illegally held stakes in coal mines, where corruption, mismanagement and other abuses contribute to thousands of deaths each year.

According to the inquiry, which stemmed from public pressure after highly publicized mining deaths, local officials routinely ignored safety hazards or covered up accidents in exchange for cash or stakes in the mines they were supposed to supervise. Results of the investigation were publicized Wednesday.

China relies on domestically produced coal for more than 70 percent of its energy needs, but the mounting death toll from accidents linked to corruption and local government coverups have embarrassed the Communist Party, even as soaring oil prices increase the country's need for less-expensive energy sources such as coal.

In one case, 121 miners drowned in a flooded pit in southern China one month after a safety official accepted a bribe to grant a license, according to a statement on the investigation issued by the State Administration of Worker Safety. Hu Jianchang, deputy director of the work-safety bureau of the southern province of Guangdong, allegedly received $12,369 on June 5 to approve the Daxing Coal Mine where the workers later died, the statement said. The state safety bureau said the case had been referred to local law enforcement authorities.

Some 2,187 miners were killed in accidents through the first five months of the year, according to the worker-safety administration. Last year, 6,027 miners were killed.

Initially, poor safety measures and mismanagement were widely blamed for the deaths. But Li Yizhong, head of the worker-safety administration, was quoted in the statement as saying corruption was the root cause of the negligence.

The government has mounted a campaign to shut down unlicensed mines, where safety conditions tend to be worst, but it said local authorities working in collusion with mine owners have hampered that effort. In response, Beijing is forcing officials and heads of state-owned companies to surrender their shares in coal mines. Some are holding on to their stakes because bankrupt or start-up mines don't have the cash to buy back their shares, worker-safety officials said.

They said more cases of illegal ownership of mine stakes by public officials are likely to come to light.

"We're aiming to get rid of all the cadre-held shares in coal mines, but considering the complicated situation, we don't expect the work could be finished in just months," a safety-administration official said Wednesday.

Han Dongfang, a Hong Kong labor rights activist, welcomed the government's move but said Beijing must increase supervision in the mines to improve the safety record. He said one way to do this would be to let workers report violations.

Separately, China's largest coal exporter, China National Coal Group, delayed until next year its plan to list its shares on the Hong Kong stock market, Zhou Dongzhou, a deputy managing director of a trading arm of the company, was quoted by Reuters as saying Wednesday. Zhou said the group needed more time to prepare for listing.

Rescue workers gathered at the Shenlong Coal Mine in western China after a July explosion killed dozens of miners.