By Alexandria Sage

SAN FRANCISCO (Reuters) - Up to 134 million U.S. consumers may venture out to shop for holiday gifts this weekend, although many are checking for bargains first, according to a survey released on Tuesday.

The poll by the National Retail Federation on shopping plans for the three days after the Thanksgiving Day holiday -- Black Friday, Saturday and Sunday -- found 57 million consumers planning to hit the stores.

Another 77 million said that before heading out, they would make sure retailers were offering discounts.

That is up from last year's survey in advance of Black Friday, when 49 million consumers planned to shop and an additional 79 million said they might if promotions were tempting.

The weekend after Thanksgiving, considered the kickoff to holiday shopping, is expected to draw bargain-hungry consumers who have cut back on their spending over the past year amid rising unemployment, curtailed credit and a weak economy.

Industry experts say the three-day weekend could draw a strong turnout, but many still expect tepid sales for the entire holiday season leading up to Christmas.

The Standard & Poor's Retail Index is up 45 percent this year, compared with a 23 percent rise in the S&P 500 Index, on hopes consumer spending will rebound in the coming months and boost the U.S. economy. Both indexes were slightly lower on Tuesday.

NOT A GROWTH ENVIRONMENT

In a separate report, SpendingPulse found that U.S. retail sales showed signs of stabilizing in the first half of November in the run-up to the holiday season.

While sales at many retailers, such as those selling women's clothing, fell in the first half of November, most showed smaller year-over-year declines, suggesting there won't be the same retail bloodbath this year as last.

"The data is showing that we are in an environment of stable consumer spending but not one of growth," said Kamalesh Rao, director of economic research for SpendingPulse, an information service provided by MasterCard Advisors.

SpendingPulse estimates retail sales for all forms of payment, including cash, checks and credit cards.

The National Retail Federation survey found that discounters and department stores will see the most shoppers, with 66.3 percent of those polled opting for the former and 62.4 percent for the latter.

More than 40 percent said they would head to electronics stores and 36 percent said they would seek out clothing or accessories. Some 27 percent said they would shop online.

Many retailers will open at midnight on Thanksgiving Day, and 10 percent of shoppers said they would be willing to shop between midnight and 3 a.m. -- mostly 18- to 34-year-olds, the report found.

More than a quarter of shoppers said they planned to shop in the early-morning hours for early-bird specials.

The NRF survey, conducted by consumer market research firm BIGResearch, polled 8,692 consumers November 3-10. The poll has a margin of error of plus or minus 1 percent.

(Reporting by Alexandria Sage; Additional reporting by Phil Wahba; Editing by Steve Orlofsky and John Wallace)