New York City regained full electrical power late on Friday, nearly 29 hours after the biggest city in the United States experienced the worst blackout in North American history, power company officials said.

"It was restored at 9:03 p.m. (0103 GMT) to all 3.1 million customers in New York City and Westchester," said Michael Clendenin, spokesman for Consolidated Edison Co. of New York Inc.

The company attributed the restoration of power supply to round-the-clock endeavor by Con Edison employees, and pledged their continued efforts through the weekend to stabilize the supply system and prevent any further disruptions.

The company has also renewed its appeal to customers for energy conservation as it examines and addresses the effects of the power supply disruption.

Consolidated Edison serves the five New York City boroughs and Westchester County to the north.

The power outage, the biggest ever to hit North America, occurred on Thursday afternoon at 4:11 p.m. (2011 GMT), cutting power supply throughout the northeastern United States and southeastern Canada.

(Xinhua News Agency August 16, 2003)