However, the North American Electric Reliability Council said there are several areas of concern with regard to the dependability of the transmission system, whose vulnerability was exposed last August, when 50 million people in New Jersey, seven other states, and parts of Canada were thrust into darkness.

"Even in areas where resources are expected to be adequate to serve all customer demand, unanticipated equipment problems and extremely hot weather can combine to produce situations in which demands temporarily exceed available generation and transmission capacity," the group said in its report.

The final report leveled much of the blame on FirstEnergy Corp., which it said failed to adequately recognize or respond to problems on three of its lines in Ohio. Investigators also found inadequate monitoring of events by the regional grid system operator.

FirstEnergy, the parent of Morristown-based Jersey Central Power & Light Co., has contended that the grid problems were more widespread.

One irony is that most of JCP&L's one million customers in the state kept their power, but more than a third of Public Service Electric and Gas Co.'s two million customers lost power despite the fact that its system functioned as designed, stopping the outage from cascading beyond the northern part of the state.

Industry experts said Tuesday that although grid operators have upgraded technology and become better coordinated since the Aug. 14 blackout, widespread outages are still a risk.

Most distressing is that nine months after the largest blackout in U.S. history, the nation still lacks mandatory reliability standards, experts said.

NERC alluded to this problem in its report.

"If all entities comply with NERC reliability standards, there should be no uncontrolled blackouts," the report said.

That view is consistent with the findings of the joint U.S.- Canadian task force that investigated last summer's blackout. In its final report, the task force concluded that a significant cause of last summer's blackout was the power industry's disregard of rules intended to ensure the reliable flow of electricity.

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Staff Writer Kevin G. DeMarrais contributed to this article.