In the nights before Christmas, some U.S. retailers are opening their doors round the clock to wring out every last possible holiday sale.

But few consumers are burning the midnight oil in their hunt for bargains, and a visit to New York City stores showed only a handful of tourists, late night revelers and desperate last-minute shoppers wandering the aisles.

Macy's Inc's flagship store in Manhattan's Herald Square began operating 24 hours a day on Monday and will close on Christmas Eve at 6 p.m.

Across the United States, Macy's kept 12 stores open in metropolitan areas such as New York, Washington, D.C. and Philadelphia, out of a chain of about 800 outlets.

Other store chains with a number of locations open round the clock this week include consumer electronics chain Best Buy Co Inc and Kmart .

The Manhattan Macy's store, often known for its daylight shopping frenzy, was calm at 12:30 a.m. EST on Wednesday. Sales clerks even had time on their hands to fold sweaters into a pile. But some shoppers said that was a draw.

When you come here in the afternoon, it's shoulder to shoulder, said Phil Reeves, a car dealership manager visiting from Australia.

It's more relaxed and from our point of view we can do other things during the day. The extended hours let him and his family see a Broadway musical before heading into stores.

Greg Hatton, a truck driver from Guelph, Ontario, said he was with his girlfriend making impulse purchases after some barhopping.

That convenience is a key advantage that the retailers are seeking as they face heightened competition from web commerce, sales lost in last weekend's East Coast snowstorm and consumers focused on deep discounts.

What retailers are looking to do is get any leg up on the competition to get what little dollars are available, said Marshal Cohen, chief industry analyst at the NPD Group.

We're seeing a new tradition form right in front of our eyes, he said of the extended hours and the decision by a rising number of retailers to open even on U.S. Thanksgiving Day and Christmas.

Cohen said that aside from a few hours of extra wages, incremental costs to retailers are minimal but create invaluable goodwill.

Overall the National Retail Federation expects U.S. retail sales to fall 1 percent to $437.6 billion this holiday season from a year ago. In two weeks, retailers are set to release December sales results.

FEWER HASSLES

A number of Macy's rivals opted not to stay open around the clock in the run up to Christmas and may have lost some customers as a result.

J.C. Penney's store in Herald Square, one block south of Macy's, shut its doors at midnight, a closure some shoppers found inconvenient.

I'm from the Midwest and there you can go to a Target or a WalMart in the middle of the night, said Sarah O'Haver, who was leaving the Penney store with several shopping bags at the stroke of midnight.

They call this the city that never sleeps but you can't even find a 24-hour grocery store, she said, adding that she would probably pop up into Macy's to round out her shopping because it was still open.

Few stores in the area from Herald Square to Times Square were open and there were signs that retailers were going further to capture holiday sales.

The Gap Inc offered 60 percent off on some merchandise at its namesake stores in Times Square and Herald Square stores in discounts reminiscent of last year's fire sales.

Others relied on special events to lure shoppers after hours and fill up their stores.

Foot Locker Inc's Times Square store remained open until midnight and offered 70 percent discounts on some items. A crowd of young adults snaked around the corner of its 34th Street store, which stayed open until the early hours, waiting to buy the newly launched Air Jordan XI Space Jam sneakers.

I'm in line now because it'll be sold out tomorrow, one youth said.

At the Toys R Us Inc in Times Square, a number of parents were taking advantage of the modest crowds and lack of children to get their toy shopping done early Wednesday.

I'm a single dad and I just got off a date, said John Reynolds, a radio programer from New York. The absence of kids and later hours means you can walk more freely.

One investment banker, who declined to give his name saying his colleagues would not let him live down shopping for toys in the wee hours, made a date of it with his wife after going to a restaurant.

(Editing by Michele Gershberg and Steve Orlofsky)