The rules are intended to prevent phone and cable companies from using their control over broadband connections to dictate where their subscribers go and what they do online. They prohibit broadband providers from favoring or discriminating against Internet content and services, including online calling services like Skype and Web video services like Netflix that could compete with their core phone and cable operations.

Wednesday’s vote marks the second attempt by House Republicans to reverse the FCC’s actions. Last month, they attached an amendment to a sweeping spending bill that would prohibit the agency from using government money to implement its new regulations.

Republicans argue that the rules will discourage phone and cable companies from investing in costly network upgrades by barring them from offering premium services over their lines or prioritizing traffic from business partners in order to earn a return on those investments. They also maintain that the FCC overstepped its authority in adopting the rules.

Verizon Communications Inc. and Metro PCS Communications Inc. are also challenging the rules in federal appeals court in the District of Columbia.

Last year, that same court ruled that the FCC had exceeded its legal authority in rebuking cable giant Comcast Corp. for blocking its subscribers from accessing an Internet file-sharing service used to trade online video and other big files. Comcast maintained that traffic from the service was clogging its network.

The agency said Comcast had violated broad net neutrality principles first established by the commission in 2005. Those principles served as a foundation for the formal rules adopted by the FCC late last year.

The FCC’s three Democrats voted to adopt the rules over the opposition of the agency’s two Republicans just before Christmas. Republicans in Congress, who now control the House, have vowed to try to block the rules from taking effect. They argue that they amount to unnecessary regulation that will discourage phone and cable companies from investing in their networks.

Several key House Republicans, including House Commerce Committee Chairman Fred Upton of Michigan, welcomed Verizon’s actions Thursday as “a check on an FCC that is acting beyond the authority granted to it by Congress.” The court challenge had been widely expected.

In a statement, Verizon said that while it is “committed to preserving an open Internet,” it remains “deeply concerned by the FCC’s assertion of broad authority for sweeping new regulation of broadband networks and the Internet itself.”

The company is taking the case to the same federal court that ruled last year that the FCC had exceeded its legal authority in sanctioning cable giant Comcast Corp. The agency had cited Comcast for discriminating against online file-sharing traffic on its network — violating broad net neutrality principles first established by the agency in 2005. Those principles served as a foundation for the formal rules adopted by the commission last month.

Last year’s court ruling forced the FCC to look for a new framework for regulating broadband to ensure the commission would be on solid legal ground in adopting net neutrality and other rules. The agency currently treats broadband as a lightly regulated “information service,” as opposed to phone service, which is more heavily regulated as a so-called “common carrier.”

At one point, FCC Chairman Julius Genachowski proposed redefining broadband as a telecommunications service subject to common carrier obligations to treat all traffic equally. But he later backed down in the face of fierce opposition from the phone and cable companies, as well as many Congressional Republicans.

And he now argues that the agency has ample authority to mandate net neutrality under the existing regulatory framework for broadband — an assumption that will be tested in the Verizon challenge.

A senior FCC official said Thursday that the agency is confident that its new net neutrality rules are legally sound and is prepared to defend them.

The rules represented an attempt to craft a compromise on an issue that has divided the telecommunications and technology industries. On one side, Internet companies such as Skype, as well as public interest groups, argue that strong rules are needed to prevent broadband providers from becoming online gatekeepers that can dictate where people go and what they do online.

But the big phone and cable companies insist that they need flexibility to manage Internet traffic to keep their networks running smoothly and preventing bandwidth-hogging applications from slowing down their systems. They also maintain that they should be able to charge extra for special services over their broadband lines and earn a healthy return on the billions of dollars they have spent on network upgrades.

New York-based Verizon is the country’s fourth-largest fixed-line Internet service provider, with 8.3 million subscribers. It’s investing more in home broadband than any other company, since it’s upgrading about two-thirds of its local-phone network with optical fiber for ultra-fast Internet access.

The regulations adopted last month try to find a middle ground. The rules require broadband providers to let subscribers access all legal online content, applications and services over their wired networks. But they give providers flexibility to manage data on their systems to deal with network congestion and unwanted traffic, including spam, as long as they publicly disclose how they manage the network.

The new rules do prohibit unreasonable network discrimination — a category that would likely include “paid prioritization,” which favors the broadband providers’ own traffic or the traffic of business partners that can pay extra — but they do not explicitly bar the practice.

The regulations also prohibit wireless carriers from blocking access to any websites or competing services such as Internet calling applications on mobile devices, and they require carriers to disclose their network management practices, too. But they give wireless companies more flexibility to manage data traffic because wireless systems have less network bandwidth and can become overwhelmed with traffic more easily than wired lines.

The outcome caps a nearly-16-month push by Genachowski to pass “network neutrality” rules and marks a key turning point in a policy dispute that began more than five years ago.

“The open Internet is a crucial American marketplace, and I believe that it is appropriate for the FCC to safeguard it by adopting an order that will establish clear rules to protect consumers’ access,” Commissioner Mignon Clyburn, a Democrat, said in a statement.

Yet many supporters of network neutrality are disappointed. Clyburn and the other Democrat, Michael Copps, both said the rules are not as strong as they would like, even after Genachowski made some changes to address their concerns.

That sentiment was echoed by some public interest groups on Tuesday.

“The actions by the Federal Communications Commission fall far short of what they could have been,” said Gigi Sohn, president of Public Knowledge. “Instead of strong, firm rules providing clear protections, the commission, created a vague and shifting landscape open to interpretation.”

A number of big Internet companies, including Netflix Inc., Skype and Amazon.com Inc., have previously expressed reservations about the proposal as well.

Meanwhile, even the weakened rules are likely to face intense scrutiny as soon as the Republicans take over the House next year.

The chairman’s proposal builds on an attempt at compromise crafted by outgoing House Commerce Committee Chairman Henry Waxman, D-Calif., as well as a set of broad net neutrality principles first established by the FCC under the previous administration in 2005.

The rules would require broadband providers to let subscribers access all legal online content, applications and services over their wired networks — including online calling services, Internet video and other Web applications that compete with their core businesses.

But the plan would give broadband providers flexibility to manage data on their systems to deal with problems such as network congestion and unwanted traffic like spam as long as they publicly disclose their network management practices.

Senior FCC officials stressed that unreasonable network discrimination would be prohibited.

They also noted that this category would most likely include services that favor traffic from the broadband providers themselves or traffic from business partners that can pay for priority. That language was added to help ease the concerns of Genachowski’s two fellow Deomcrats.

The proposal would, however, leave the door open for broadband providers to experiment with routing traffic from specialized services such as smart grids and home security systems over dedicated networks as long as these services are separate from the public Internet.

Public interest groups fear that exception could lead to a two-tiered Internet with a fast lane for companies that can pay for priority and a slow lane for everyone else.

They are also worried that the proposal lacks strong protections for wireless networks as more Americans go online using mobile devices.

The plan would prohibit wireless carriers from blocking access to any websites or competing applications such as Internet calling services on mobile devices. It would require them to disclose their network management practices too.

But wireless companies would get more flexibility to manage data traffic as wireless systems have more bandwidth constraints than wired networks.

“Individuals who depend on wireless connections to the Internet can take no comfort in this half-measure,” said Joel Kelsey, political advisor for the public interest group Free Press.

Republicans, meanwhile, warn that the new rules would impose unnecessary regulations on an industry that is one of the few bright spots in the current economy, with phone and cable companies spending billions to upgrade their networks for broadband.

Burdensome net neutrality rules, they warn, would discourage broadband providers from continuing those upgrades by making it difficult for them to earn a healthy return on their investments.

Still, Genachowski’s proposal is likely to win the support of the big phone and cable companies because it leaves in place the FCC’s current regulatory framework for broadband, which treats broadband as a lightly regulated “information service.”

The agency had tried to come up with a new framework after a federal appeals court in April ruled that the FCC had overstepped its existing authority in sanctioning Comcast Corp. for discriminating against online file-sharing traffic on its network — violating the very net neutrality principles that underpin the new rules. Comcast argued that the service, which was used to trade movies and other big files over the Internet, was clogging its network.

To ensure that the commission would be on solid legal ground in adopting net neutrality rules and other broadband regulations following that decision, Genachowski had proposed redefining broadband as a telecommunications service subject to “common carrier” obligations to treat all traffic equally. But Genachowski backed down after strong opposition from the phone and cable companies, as well as many Republicans in Congress.