WASHINGTON — Phone and cable TV companies that provide Internet access should be barred from slowing down, blocking or charging to prioritize Internet traffic flowing over their regular broadband lines, Verizon Communications Inc. and Google Inc. said in a policy statement released Monday.

But the firms left room for broadband providers to charge extra to route traffic from premium services such as remote medical monitoring and smart-grid controls over dedicated networks that are separate from the public Internet.

Verizon and Google laid out their vision in a policy proposal that they hope can serve as a framework for Congress and the Federal Communications Commission in drafting so-called “network neutrality” rules.

Such rules are meant to ensure that phone and cable providers cannot favor their own services or discriminate against Internet phone calls, online video and other Web services that compete with their core businesses.

Although broadband providers such as Verizon and Internet-content companies such as Google are at opposite ends in the debate over such rules, the two companies have been in talks for months to try to identify common ground.

Their proposal comes just days after the FCC declared an impasse in negotiations to craft an industry-wide compromise on the thorny issue. FCC Chairman Julius Genachowski is seeking to adopt net-neutrality rules that would ensure that broadband subscribers could readily access all legal online content.

The proposal from Google and Verizon would give the FCC authority to enforce those rules for wired networks.

The proposal would allow the agency to impose a penalty of up to $2 million on companies that violate the rules. Wireless carriers, which have more capacity constraints, would not be subject to the restrictions, although they would have to disclose their practices.

In a conference call with reporters, Google CEO Eric Schmidt and Verizon CEO Ivan Seidenberg said their proposal would preserve the openness of the Internet, but still give phone and cable TV companies room to experiment with “managed” services that could send video, games and other bandwidth-hungry applications over separate systems.

But several public interest groups were quick to denounce the proposal. In a statement, Free Press Political Adviser Joel Kelsey said the plan would “transform the free and open Internet into a closed platform like cable television” and “lead to toll booths on the information superhighway.”

Gigi B. Sohn, president and co-founder of the group Public Knowledge, said the proposal “sacrifices the future of the mobile wireless Internet.”PROHIBITED: Verizon Communications Inc. and Google Inc. are offering a policy proposal that would bar phone and cable TV companies from slowing, blocking or charging to prioritize Internet traffic flowing over their regular broadband lines.

PERMITTED: The proposal would allow broadband providers to charge extra to route traffic from premium services such as remote medical monitoring and smart grid controls over dedicated networks that are separate from the public Internet.

WHAT’S NEXT: The firms hope their plan can be a framework for Congress and the FCC to draft “network neutrality” rules for handling Internet traffic.