MELBOURNE (Reuters) - Caught Twittering or on Facebook at work? It'll make you a better employee, according to an Australian study that shows surfing the Internet for fun during office hours increases productivity.

The University of Melbourne study showed that people who use the Internet for personal reasons at work are about 9 percent more productive that those who do not.

Study author Brent Coker, from the department of management and marketing, said "workplace Internet leisure browsing," or WILB, helped to sharpened workers' concentration.

"People need to zone out for a bit to get back their concentration," Coker said on the university's website (www.unimelb.edu.au/)

"Short and unobtrusive breaks, such as a quick surf of the Internet, enables the mind to rest itself, leading to a higher total net concentration for a days' work, and as a result, increased productivity," he said.

According to the study of 300 workers, 70 percent of people who use the Internet at work engage in WILB.

Among the most popular WILB activities are searching for information about products, reading online news sites, playing online games and watching videos on YouTube.

"Firms spend millions on software to block their employees from watching videos, using social networking sites or shopping online under the pretence that it costs millions in lost productivity," said Coker. "That's not always the case."

However, Coker said the study looked at people who browsed in moderation, or were on the Internet for less than 20 percent of their total time in the office.

"Those who behave with Internet addiction tendencies will have a lower productivity than those without," he said.

(Writing by Miral Fahmy; Editing by Valerie Lee)