USA TODAY

SAN FRANCISCO — Despite a yearlong federal crackdown on the troubled power industry, energy traders and companies still might be manipulating natural gas prices, energy regulators say.

“Evidence indicates that price manipulation has occurred in certain natural gas marketplaces, and may be continuing,” says a report issued Wednesday by the Federal Energy Regulatory Commission and its Office of Market Oversight and Investigations.

The office was formed last year to monitor the energy markets for trading abuses.

Energy companies could be manipulating wholesale natural gas prices by intentionally reducing the storage and distribution of natural gas, the report states, or by sharing sensitive market information with trading partners or subsidiaries.

The report and FERC officials did not disclose the names of any additional companies or traders under investigation. FERC spokesman Kevin Cadden confirmed only that “investigations are ongoing.”

“This does not mean the marketplace is rife with abuse,” FERC commissioner Nora Mead Brownell said in a statement. “It means the people who are being paid to look out for problems are doing their jobs.”

In the past year, FERC and other federal and state authorities have been investigating allegations of market manipulation and sham accounting practices at energy-trading companies. So far, federal prosecutors have filed criminal charges related to former employees of Enron, El Paso and Dynegy.

Despite the many problems, the FERC report says, there should be no nationwide shortage of natural gas this winter. But a lack of pipelines and the constant, shifting demand for power might lead to shortfalls of natural-gas transmission in New York City, New England, the Southeast and Colorado.

Critics say the FERC report confirms their belief that deregulated energy trading hurts consumers and businesses. Wild energy trading in California from the late 1990s to 2001 led to wholesale price spikes that cost the state tens of billions of dollars, say consumer advocates and California lawmakers.

“If we continue on a path toward deregulation, we are going to see more crooked behavior and higher costs for consumers,” says Doug Heller of the Foundation for Taxpayer and Consumer Rights in Los Angeles.

In 2001, corporate and residential customers in the USA spent $ 142 billion on natural gas, or 1.4% of the nation’s gross domestic product, the report said.