Colette Bowe, chairman of the communications watchdog's independent Ofcom Consumer Panel, has asked the top six UK broadband CEOs to come up with systems that give customers clear information.
The decision to write to them follows increasing consumer concern about broadband speeds. The "up to" speeds advertised in broadband packages are often wildly different from the actual, lower speeds experienced by many subscribers.
In her letter to the CEOs, she says, "we believe that broadband customers are not at the moment getting enough information. We are of course aware of the technical reasons for the "up to" terminology that you use.
"I would, however, like to have your views about how these technical issues might be better addressed in terms of giving clearer information to potential customers."
The Consumer Panel has asked providers to consider changing their sales practices to include advising customers what their likely connection speed would be on a specific line.
They also want providers to extend the cooling off period so that customers can test out the connection speed before they sign a contract, and allow customers to later exit from contracts if they experience speeds well below the advertised speeds, without any penalty.