The BBC’s decision to broadcast World Cup games over the internet could slow down corporate IT networks, experts have warned.

The BBC announced that it will stream all its TV games live online, and will offer video highlights from its web site after the matches.

Roger Mosey, director of BBC Sport, said that the decision gives UK licence-payers more choice. “Some people will want to watch the afternoon World Cup games on the PC in their office; others will drive home listening to coverage on Five Live or Five Live Sports Extra; and if you've been out for the evening you'll be able to catch up with all the goals at the time you want rather than where we've chosen to schedule them,” he wrote in a blog post.

Only one England game is scheduled to be streamed so far, as ITV has the rights to the other two Group B games.

However, IT experts warned that the BBC’s service would cause problems for some firms.

Network specialist Packeteer said live World Cup matches could reduce productivity if it causes network congestion and slows important applications.

"It is likely that millions of workers will log on to watch matches due to faster internet connections at work than at home,” said Mike Hemes, country manager for the UK and Ireland at Packeteer. “This will generate a huge surge in network traffic, eating into the bandwidth available to run business-critical applications effectively."

Hemes advised firms to ensure that IT managers have tools in place to control internet traffic, protect the network from overload and prioritise bandwidth for critical applications.

Law firm Osborne Clarke advised employers to take a balanced approach - perhaps reminding staff of acceptable usage policy for the internet, and also setting up dedicated viewing facilities so they could still watch games at the office.