Comcast mulling Net usage cap to discourage 'excessive' use

If users exceed that cap, they could be charged $15 for every 10 gigabytes they go over.

Because the plan is still in its early stages, Comcast could still change the details or decline to impose any caps or charges.

Time Warner Cable Inc. is on track this year to roll out a test run of a plan to charge different rates depending on Internet use, said spokesman Alex Dudley.

The trial in Beaumont, Texas, will offer five-, 10-, 20-, or 40-gigabyte plans to new customers priced tentatively from $29.95 to $54.95 a month. Those who go over will be charged a fee. Subscribers can check their bandwidth use through a Web site.

New York-based Time Warner said 5 percent of subscribers use 50 percent of the bandwidth.

Cox Communications in Atlanta said it has had usage caps on its Internet plans for three years. Consumers who go over the limit will be warned first, usually by e-mail, after which they will have service suspended until they call customer service. Spokesman David Grabert said customers appreciate that Cox has "clearly communicated ... what our limits are."

Bend Cable Communications, a cable operator in Bend, Ore., is already charging $36.95 to $74.95 a month for plans ranging from 10 to 100 gigabytes, with subscribers who go over the limit charged $1.50 per gigabyte.

Shares of Comcast fell 28 cents to $21.57 on Wednesday.