The average broadband speed for British consumers is 3.6 Megabits per second (Mbit/s), sufficient for many applications but well below advertised speeds, regulator Ofcom said on Thursday.

According to research based on 10 million separate tests of a range of suppliers' services, broadband speeds via DSL and cable vary by time of day due to the traffic levels on the network.

Across Britain, the speeds were slowest between 5 and 6 pm on Sunday, when use of the Internet is at its highest, the report said.

Ofcom said "3.6 Mbit/s is sufficient for many Internet applications, including audio and standard definition video," but noted that "the speeds achieved are significantly below advertised headline speeds."

The average maximum possible speed was 4.3 Mbit/s -- the highest speed that the line was capable of during the research period.

Ofcom said over 60% of U.K. broadband consumers subscribed to "up to 8Mbit/s" packages but that on average the actual speed consumers received was 45% of the advertised offer. One in five subscribers actually received an average speed of less than 2Mbits/s.

For customers on DSL lines and not cable, speeds also depend in part on distance to the local BT exchange and consumers living in urban areas received speeds which were on average 15% faster than those in rural areas.

Consumers in London received the fastest average speeds while those in the north east of England, Wales and Scotland received on average the slowest speeds.

Ofcom has introduced a Code of Practice guide to give consumers more information on broadband speeds.

BT has announced plans to roll out a superfast broadband service by 2012 to 10 million homes to enable services such as video conferencing and interactive gaming. Cable operator Virgin Media recently rolled out a 50 Mbit/s offering.