More last-minute shoppers flocked to stores this year on the final Saturday before Christmas than last year, but spending is expected to be even higher late this week.

U.S. retail sales on Saturday were up 15.1 percent from last year to $7.58 billion as many people wrapped up their gift buying, research firm ShopperTrak said on Tuesday. This year also benefited from its comparison to the weekend in 2009 when a blizzard hammered the East Coast.

That storm contributed to a 16.5 percent drop to $6.58 billion in so-called Super Saturday spending in 2009. This year's totals were below the $7.87 billion Americans spent for the day in 2008, said ShopperTrak, which analyzes the retail industry.

Yet with less than a week to go until Christmas, many shoppers are still procrastinating. Some eleventh-hour gift seekers will even be out on Christmas Eve - about 23 million, according to a separate survey on Tuesday from the International Council of Shopping Centers.

Now that we are down to the wire, consumers have stepped up their shopping pace, as well as their purchases, ICSC chief economist Michael Niemira said in a statement. All and all, retail shopping trends are shaping up to be very favorable for holiday sales, as well as December sales performance, for retailers.

Consumer spending makes up about 70 percent of the U.S. economy and analysts have said they expected the 2010 holiday season to show the biggest sales gains since 2007.

December 23 is likely to be the year's second biggest day in sales and third biggest in foot traffic, said ShopperTrak founder Bill Martin.

Black Friday, the day after Thanksgiving that traditionally kicks off the holiday shopping season, saw $10.69 billion in sales, according to ShopperTrak, making it the biggest shopping day so far this year. It is called Black Friday because retailers hope it will put their accounts solidly in the black through strong sales.

Saturday's foot traffic was up 10.1 percent compared with last year, ShopperTrak said.

Nearly three quarters of Americans completed their shopping by the end of Super Saturday, according to the ICSC. The previous week, 56.6 percent had finished their holiday shopping.

The Saturday shopping binge boosted sales for the entire week, which rose 4.2 percent from a year ago, according to an ICSC-Goldman Sachs weekly chain store sales index.

As usual, the spending will not end on Christmas, the ICSC also found. Nineteen percent of consumers plan to go shopping the day after, and 47 percent said they would be out the week between Christmas and New Year's.

(Reporting by Jon Lentz)

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