UPDATE 2-ConEd says power to resume for most NY customers by Nov. 11
* Lower Manhattan to have power by Saturday

* 650,000 still without service in NYC and Westchester

* Nationwide, 4.7 million without power in 12 states

* In hard-hit states, NY and NJ, no service for 1.5 million

Nov 1 (Reuters) - Consolidated Edison Inc said Thursday most of its customers in New York City and Westchester County, New York, will have power back by Nov. 10-11, after Hurricane Sandy slammed into the U.S. East Coast earlier in the week, causing widespread damage and flooding.

The New York utility said it expected to restore power in lower and mid-Manhattan by Saturday, Nov. 3.

Earlier, the company had said it expected power to be restored to lower Manhattan by Friday or Saturday and that it would take at least a week to restore power to areas with overhead lines like Westchester.

But on Thursday morning, Con Edison said it expected to make significant progress restoring electricity over the next two days, with its latest estimate based on a recent assessment of the damage caused by the massive storm.

About 900,000 customers lost power after Sandy walloped the area, Con Edison said, making the storm the worst natural disaster in the company's history.

The company said its crews had restored power to about 250,000 customers, and, as of 11:00 a.m. EDT, the company was working to restore power to another 650,000 customers.

New York City Mayor Michael Bloomberg said Thursday the New York Marathon remained on schedule for Sunday and that the event would not ``redirect any focus'' from the city's safety and recovery efforts.

The city's schools are scheduled to reopen Monday, Nov. 5.

Public schools have been shut since Monday, Oct. 29, when the massive storm slammed into the U.S. East Coast, killing more than 80 people and causing billions of dollars of damage and flooding.

PUMPING OUT SEAWATER

Con Edison said crews working on the underground electric system in Manhattan had pumped massive amounts of seawater out of the facilities, and had to clean and dry all of the equipment before they could safely be put back into service.

In areas served by overhead power lines, crews had to contend with more than 100,000 downed wires, as well as blocked roads and flooding, the company said.

To help restore power, Con Edison said it had lined up more than 1,600 external contractors and mutual aid workers from utilities as far away as California.

The company did not say in its latest statement how many customers still lacked power in each borough.

As of 4:30 a.m. EDT Thursday, the utility said about 227,000 customers were still out in Manhattan, 103,000 in Queens, 59,000 in Brooklyn, 83,000 in Staten Island, 36,000 in the Bronx and 166,000 in Westchester County. (By 1:00 p.m., the total number of clients was down to 650,000.)

Sandy left more than 8.48 million customers without power in 21 states, from North Carolina to Maine, and as far west as Illinois.

There were still 4.7 million customers without power in 12 states, according to federal data Thursday morning.

The U.S. Department of Energy said there were still more than 1.5 million homes and businesses without power in the nation's two hardest hit states - New York and New Jersey.