US regulators voted Thursday for a proposal that would allow Internet "fast lanes" while leaving open the possibility of tougher regulations to protect online access. Amid demonstrations outside its meeting and following weeks of lobbying from various groups, the Federal Communications Commission voted 3-2 in favor of the new rules, which still must go through a public comment period before being finalized. The plan, which aims to replace rules struck down by a US federal court,seeks to keep some principles of "net neutrality" -- the notion that all online traffic should be treated equally -- while allowing commercial deals authorizing companies to pay for faster Internet access. The FCC said the proposed rules may allow special deals for priority access but that each would be examined for "commercial reasonableness." At the same time, the commission said it was keeping open the possibility of regulating Internet access as a public utility, which could give the FCC much greater authority over Internet access providers. The plan is touted as a means to preserve an "open Internet," but did not placate activists on either side of the issue -- those who want a guarantee of equal access, and those seeking less regulation that allows deals for faster speeds. Michael Weinberg of the activist group Public Knowledge said the proposal "remains insufficient to guarantee a truly open and neutral Internet." He said the proposal "would create a two-tier Internet where 'commercially reasonable' discrimination is allowed on any connections that exceed an unknown 'minimum level of access' defined by the FCC. A two-tier Internet is anathema to a truly open Internet." Scott Cleland, a consultant and chairman of the business group NetCompetition representing telecom and Internet firms, said the plan "is a blueprint for unnecessary uncertainty." Cleland said regulating the Internet as a utility "would require every business decision of consequence to be approved by the FCC..." "Ironically, the obvious unintended consequence here would be to put the American part of the Internet in the slowest lane filled with interminable speed bumps, potholes, stop lights, and inspection stations," he added. The proposal appeared likely to generate more protests such as the one outside FCC headquarters, where several hundred people banged drums and carried signs reading "Save the Internet." "If we start creating express lanes on the Internet, they're only going to be reserved for a small handful of big companies and those that can afford to pay them huge, huge rates," said Craig Aaron, president of the activist group Free Press.