UPDATE 3-Over 6 million remain without power in US Northeast

* Power companies say restored service to 2 million customers

* New York, New Jersey each have more than 2 million out

* More than half of New Jersey customers powerless

Oct 31 (Reuters) - About 6.2 million homes and businesses in 16 U.S. states remained without power on Wednesday as utilities scrambled to restore service disrupted by Hurricane Sandy, federal data showed.

The power companies had restored electricity to some 2.28 million customers in the U.S. Northeast, although the pace of recovery in New York appeared to lag behind other storm-hit states, the data showed.

At the storm's peak, 8.48 million customers were without power after Sandy came ashore with hurricane-force winds in New Jersey on Monday, according to Department of Energy data.

Power has been restored to nearly 600,000 customers in New Jersey, out of more than 2.6 million that lost power, although more than half the state still remains in the dark, according to the data as of 10 a.m. EDT (1400 GMT).

In New York, where Sandy knocked out power to nearly a third of the customers in New York City and Westchester County, only about 165,000 customers of the total 2.1 million that lost power in the state have seen it restored, according to the figures.

The DOE did not provide any further comment or explanation for the figures.

In New York, power company Consolidated Edison Inc said about 799,200 homes and businesses in New York City and Westchester County were still without power due to the storm's devastation.

Con Edison said its crews had restored service to about 109,000 customers by 11:00 a.m. EDT (1500 GMT) Wednesday.

That is less than the estimated 140,000 customers the company said it restored on Tuesday. Officials at Con Edison were not immediately available to explain the difference.

Con Edison said those customers still out include: about 237,000 in Manhattan, 115,000 in Staten Island, 109,000 in Queens, 108,000 in Brooklyn, 40,000 in the Bronx, and 176,000 in Westchester County.

The power company said its Courtland district, which spans from just below the World Trade Center to the lower tip of Manhattan, regained power Wednesday morning, and restoration of the company's Brighton Beach district in Brooklyn is expected by 4 p.m., said John Miksad, senior vice president of electric operations at Con Edison.

Customers in Manhattan and Brooklyn, who are served by underground electrical equipment, should have power back within three days.

Restoration to all customers in other areas served by overhead power lines like Westchester and Staten Island will take at least a week.

Miksad said there was a large crew assembled at Con Edison's 14th Street station, the site of a large explosion that caused most of lower Manhattan's power outages, and customers served by this station are expected to regain power by Friday or Saturday.

For areas served by underground wires, Con Edison said workers must clean and dry equipment of seawater before it can be safely placed back in service.

``In 120 years we've never seen damage this significant,'' Miksad said.

Con Edison said Sandy was the largest storm-related outage in its history. The previous record was the more than 200,000 customers affected by Hurricane Irene in 2011.

Irene left more than 8.38 million customers out along the U.S. East Coast from South Carolina to Maine.

Tuesday night, Con Edison said it cut power to about 160,000 customers in southern Brooklyn and central Staten Island due to Sandy-related problems on high-voltage systems supplying electricity to those areas.

The company also said it reduced the voltage in several neighborhoods in Brooklyn by 8 percent Tuesday night as workers fixed problems there.

The company said Sandy knocked down more than 100,000 electric wires. Some roads were blocked by trees or flooding, slowing those working to restore power in areas served by overhead wires like Westchester.

Con Edison said it has secured assistance from 1,400 external contractors and mutual aid workers from utilities as far west as California to help with the restoration efforts.