US telecom regulators, in a vote split on party lines, approved rules Tuesday that supporters said are needed to ensure an open Internet but opponents decried as unnecessary government intervention.

The five-member Federal Communications Commission (FCC) agreed to the rules aimed at safeguarding "network neutrality," the principle that lawful Web traffic should be treated equally, by a 3-2 vote at an open meeting here.

The three Democrats on the panel voted in favor of the rules, which are likely to face legal challenges and Republican opposition in Congress, while the two Republicans voted against them.

"Our action will advance our goal of having America's broadband networks be the freest and fastest in the world," said FCC chairman Julius Genachowski.

The FCC's first-ever "net neutrality" rules met with a mixed reaction, with public interest groups and some Democrats saying they did not go far enough and Republicans condemning them as government meddling in the private sector.

President Barack Obama said the FCC move "will help preserve the free and open nature of the Internet while encouraging innovation, protecting consumer choice, and defending free speech."

Representative John Boehner, a Republican from Ohio who is slated to become speaker when the Republicans take control of the House of Representatives in January, said "the new House majority will work to reverse this unnecessary and harmful federal government power grab."

The rules are a balancing act by the FCC between support for consumers and the cable and telephone companies that are the US Internet Service Providers.

One controversial rule saw the FCC endorse taking a different approach to fixed broadband and mobile broadband, giving wireless providers greater freedom to manage their networks because of spectrum issues.

Under the new rules, both fixed and mobile broadband providers are allowed to conduct "reasonable network management."

The rules would prevent fixed broadband providers from blocking lawful content, applications or services, providing their own video content at a faster speed, for example, than that of a rival.

Wireless providers may not block access to lawful websites or applications that compete directly with their own voice or video telephony services but they could block other applications or services.

Fixed broadband providers can also charge consumers according to usage, a metered pricing practice already used by some wireless carriers.

Craig Aaron, managing director of public interest group Free Press, said the rules "don't do enough to stop the phone and cable companies from dividing the Internet into fast and slow lanes, and they fail to protect wireless users from discrimination.

"No longer can you get to the same Internet via your mobile device as you can via your laptop," Aaron said.

Senator Al Franken, a Democrat from Minnesota, said "net neutrality" is the "most important free speech issue of our time" and the rules fall "far short."

"Mobile networks like AT&T and Verizon Wireless would be able to shut off your access to content or applications for any reason," he said. "For instance, Verizon could prevent you from accessing Google Maps on your phone, forcing you to use their own mapping program, Verizon Navigator, even if it costs money to use and isn't nearly as good."

Verizon said it was "deeply concerned" by the split FCC vote.

"The FCC appears to assert broad authority for sweeping new regulation of broadband wireline and wireless networks and the Internet itself," it said. "This assertion of authority without solid statutory underpinnings will yield continued uncertainty for industry, innovators, and investors."

Michael Copps, one of the Democrats on the FCC, expressed regret that the rules -- while discouraging -- did not explicitly ban "paid prioritization," the practice of a company paying for the faster delivery of its own content.

Robert McDowell, one of the Republican commissioners, described the vote as one of the darkest days in recent FCC history" and said it would open the door to "a global Internet regulatory pandemic."

"The courts will easily sink it," McDowell predicted.

"Nothing is broken in the Internet access market that needs fixing. Existing law and Internet structures provide ample protection to consumers," he said.

The FCC drafted the rules after suffering a legal setback in April when a court ruled that it had not been granted the authority by Congress to regulate the network management practices of Internet service providers.