(Reuters) - Americans plan this year to go shopping in greater numbers on Black Friday, the biggest shopping day of the year and unofficial kick-off the holiday spending season.

Some 152 million shoppers say they will hit stores on November 25, the day after U.S. Thanksgiving, up 10.1 percent from 138 million people last year, according to a survey by the National Retail Federation, an industry group.

For the November-December period, the NRF previously forecast retail sales would rise 2.8 percent to $465.6 billion, in what executives and analysts have said will be a more competitive season than last year.

Major retailers are leaving little to chance. For instance, discount retailer Target Corp and department stores Macy's Inc and Kohl's Corp are opening their doors earlier than ever, at midnight on Thanksgiving.

The survey, which polled 8,502 people between November 1 and November 8, also found that 17.3 percent of people will look for Black Friday deals on retailers' Facebook page and 11.3 percent on group buying sites such as Groupon Inc and Living Social.

(Reporting by Phil Wahba in New York; editing by Andre Grenon)