* Consumer advocates push to reclassify broadband providers as utilities
* AT&T, Comcast, others fiercely opposed to that idea
* FCC vote would seek comment on new "net neutrality" rules (Adds letter from Senate Republicans in 7th paragraph)
By Alina Selyukh
WASHINGTON, May 13 (Reuters) - U.S. efforts to set new Internet traffic rules face a lengthy tug of war between broadband providers and Republicans on one side and some tech companies and consumer advocates on the other as regulators prepare to propose the rules formally on Thursday.
Federal Communications Commission Chairman Tom Wheeler has expanded the issues and questions raised in his "open Internet" proposal to sway his two Democratic colleagues on the five-member panel, though some consumer advocates remain unhappy.
Public interest groups including Free Press plan to deliver petitions with more than 1 million signatures to the FCC and stage a protest against Wheeler's proposal that may allow Internet providers to charge some content companies for faster and more reliable delivery.
Consumer advocates worry that "fast lanes" for content companies willing to pay up would leave startups and others behind. They call on the FCC to reclassify Internet providers as utilities, like telephone companies, rather than the less-regulated information services they are now.
That plan is vehemently opposed by broadband companies, which are lobbying lawmakers and the FCC against such a possibility.
More than two dozen CEOs of broadband companies including AT&T Inc, Comcast Corp and Verizon Communications Inc wrote to FCC members on Tuesday, saying reclassification of their companies and Internet openness had "nothing to do" with each other.
Six Senate Republican leaders, including Mitch McConnell, also wrote to Wheeler on Tuesday, calling on him to abandon his "politically corrosive" net neutrality rulemaking.
Both sides are gearing up for a prolonged battle, assuming the FCC votes to move ahead with the new rules. A public comment period is expected to run through July 25, with replies to initial comments accepted until Sept. 10, according to an FCC official.
"It's the very beginning of the process," said one industry lobbyist. "This week will not be our last stand."
More than 100 technology companies including Google Inc and Facebook Inc have warned that Wheeler's proposal poses "a grave threat to the Internet." Democratic lawmakers, venture capitalists and a group of musicians and artists expressed similar worries.
Democratic commissioners Mignon Clyburn and Jessica Rosenworcel have expressed doubts about Wheeler's plan but are likely to vote in favor of formally proposing the rules as a way to launch the process of collecting public comment and more information. The commissioners have not confirmed their votes.
Republican FCC members broadly oppose the commission's efforts to set Internet traffic rules, which they see as obstacles to innovation and investments in already expensive network infrastructure. AT&T told FCC officials last week that reclassification would create regulatory uncertainty while still failing to prevent pay-for-priority deals.
Wheeler's latest draft seeks to calm Democrats' concerns by adding numerous questions about potentially reclassifying broadband providers. It also sought comments on whether "some or all" pay-for-priority deals should be presumed illegal, but maintained the tentative conclusion that some "commercially reasonable" deals should be allowed, according to an FCC official briefed on the plan.
The rules would also ban Internet providers from blocking users' access to websites or applications and would require them to disclose how exactly they manage traffic on their networks.
Comcast is the only Internet provider that has to abide by the older version of net neutrality rules until 2018, because of a condition placed on its acquisition of NBC Universal. (Editing by Ros Krasny, Matthew Lewis and Chizu Nomiyama)