Another US internet service provider has announced that it will begin throttling bandwidth for certain applications.

Cox Communications, which handles over six million businesses and residential customers, and is the third largest cable company in the US, has said that it will begin slowing certain functions from February under a new policy of " congestion management".

The company said that, if its network suffers undue congestion, it will slow bulk data transfers for network storage systems, FTP downloads, software updates and peer-to-peer transfers.

Meanwhile, what Cox deems more time-sensitive data, such as web pages, gaming, streaming videos and instant messaging, will get priority.

"The way our customers use the internet is always changing, so we have to continually assess the latest practices, and modify the way we manage our network to provide the best service," said the company in a statement.

"We have worked with technology vendors and listened to best practice discussions in industry and public forums to develop an intelligent network solution and even better service for our customers.

"The technology and policies at work in this trial also factor in the guidance provided by the Federal Communications Commission [FCC]."

Quite what action the FCC will take is unclear. The regulatory authority has already rebuked Comcast for similar practices, and is re-examining that case to determine whether VoIP traffic from competitors is being slowed.

Julius Genachowski, the new chairman of the FCC, is unlikely to change the policy of supporting network neutrality set down by his predecessor, Kevin Martin, and there is currently a bill before Congress that will set down the law on the issue.

The Cox trial will initially be limited to customers in Kansas and Arkansas, but the company said that it will extend the programme later in the year.