A majority of workers say they concentrate better working off-site than in the office, but many say loading files and software remotely slows them down and affects their productivity, a survey said on Tuesday.

Nearly half the workers questioned said they work off-site more often now than two years ago, and 40 percent said they would do so more often if business files or software loaded more quickly, said the survey conducted for Riverbed Technology Inc RVBD.O, an information technology company based in San Francisco.

Two-thirds of those surveyed said they would like to be able to work off-site more than they do now, it found.

Fifty-four percent said they concentrate better working off-site compared with being in the office, it said.

But 33 percent said accessing business files or software remotely negatively affected their productivity.

Working off-site can mean working from home, a hotel, another company location, coffee shop or other places, it said.

The online survey was conducted for Riverbed by Harris Interactive in late March and early April among 4,391 adults, 910 of whom were employed full time, normally work on-site and access business files or software stored on an employer's server, network or drives from off-site.

Respondents were selected from a Harris database of several million people who have agreed to participate in its surveys. Because the sample is based on those who agreed to be invited to participate, no estimates of theoretical sampling error can be calculated, Harris said.

Results were weighted to reflect the composition of the population of U.S. adult computer users as to region, age, education, income and other factors, it said.

(Reporting by Ellen Wulfhorst; editing by Michelle Nichols and Mohammad Zargham)