Survey: One-third of US workers shopping on the job

* More workers shopping online at work than last year

* 5 pct of employers have fired someone for shopping

By Ellen Wulfhorst

NEW YORK, Nov 24 (Reuters) - One-third of U.S. employees plan to shop online while at work this holiday season, according to research released on Tuesday.

They should be careful, as 20 percent of employers have fired someone for non-work online activity on the job, and 5 percent have fired someone for holiday shopping online at work, said the survey by CareerBuilder.com, an online jobs site.

The number of employees planning to shop online at work, 32 percent, is up from 29 percent who said so last year, said the survey of more than 3,100 employers and 4,700 workers nationwide.

More than half of workers -- 58 percent -- say they use the Internet for non-work activities while at the office, and 21 percent typically spend an hour or more on personal Internet use while at work, it said.

"While employers will take into consideration the overall performance of the employee, smaller staffs and higher productivity demands may have them taking more notice of time spent on non-work related activities," said Rosemary Haefner, vice president of human resources at CareerBuilder.

Three out of five full-time workers have social networking profiles, half say they spend time on their social networking page during the workday and 11 percent spend an hour or more doing so, the survey said.

Among employers, 16 percent said they monitor social networking profiles of employees and 14 percent said they monitor blogs. Also, 32 percent of employers said they monitor emails and 16 percent said they monitor instant messaging.

Eight percent have fired someone for non-work related emails, the survey found.

The research was conducted online by Harris Interactive on behalf of CareerBuilder between Aug. 20 and Sept. 9, 2009 among 3,163 full-time hiring managers and human resource professionals and 4,721 full-time U.S. workers.

The results had a sampling error of plus or minus 1.74 percentage points among employers and plus or minus 1.43 percentage points among workers.

CareerBuilder is owned by Gannett Co Inc (GCI.N), Tribune Company, The McClatchy Co (MNI.N) and Microsoft Corp (MSFT.O).

(Editing by Eric Beech)

((ellen.wulfhorst@reuters.com; +1 646 223 6283; Reuters Messaging: ellen.wulfhorst.reuters.com@reuters.net))