WASHINGTON -- Phone and cable companies expressed concern about proposed rules that would prohibit Internet service providers from slowing competitors' Web traffic or impeding access to legal Web content.

Federal Communications Commission Chairman Julius Genachowski, in a speech Monday, proposed putting teeth into current guidelines on so-called net neutrality by making them full-fledged rules, and extending them to wireless carriers.

"The bar needs to be set very high when it comes to additional government intervention," said USTelecom, the phone industry's lobbying group. Cable giant Comcast Corp. said it will "be incredibly important for the agency to review the data to determine whether there are actual and substantial problems that may require rules."

Large phone and video providers, including Comcast, Verizon Communications Inc. and AT&T Inc., have argued the government shouldn't tell them how to manage their Internet networks. Wireless providers are worried that a surge in bandwidth-consuming applications such as video downloads could hobble their networks unless they are allowed to control the flow.

For consumers, the proposed FCC action would mean that any Internet provider -- whether wireless, cable or DSL -- would be prohibited from blocking or slowing access to video or phone services. For example, Comcast or AT&T couldn't feed video to a subscriber from one of their online video services faster than they allow feeds from a rival service, such as Netflix Inc.