A divided Federal Communications Commission has approved new rules meant to prohibit broadband companies from interfering with Internet traffic flowing to their customers.

The 3-2 vote Tuesday marks a major victory for FCC Chairman Julius Genachowski, who has spent more than a year trying to craft a compromise.

The FCC's three Democrats voted to pass the rules, while the two Republicans opposed them, arguing that they amount to unnecessary regulation. The new rules are likely to face intense scrutiny on Capitol Hill once Republicans take over the House. Meanwhile, public interest groups decried the regulations as too weak, particularly for wireless systems.

Known as "net neutrality," the rules prohibit phone and cable companies from favoring or discriminating against Internet content and services, such as those from rivals.

Genachowski said the regulations will prohibit broadband providers from abusing their control over the on-ramps that consumers use to get onto the Internet. He said the companies won't be able to determine where their customers can go and what they can do online.

"Today, for the first time, we are adopting rules to preserve basic Internet values," Genachowski said. "For the first time, we'll have enforceable rules of the road to preserve Internet freedom and openness."

Still, the final rules came as a disappointment to public interest groups. Even Genachowski's two Democratic colleagues on the five-member FCC were disappointed, though they still voted to adopt the rules after concluding some safeguards are better than none.

They warn that the new regulations may not be strong enough to prevent broadband companies from picking winners and losers on the Internet, particularly on wireless systems, which will have more limited protections. They also worry that the rules don't do enough to ensure that broadband providers cannot favor their own traffic or the traffic of business partners that can pay for priority — resulting in a two-tiered Internet.