WASHINGTON  The Federal Communications Commission voted 3 to 2 on Thursday to move toward giving itself the authority to regulate the transmission component of broadband Internet service, a power the commission’s majority believes is central to expanding the availability of broadband.

The vote formally begins a period of public comment on an F.C.C. proposal to overturn a previous commission ruling that classified broadband transmission as a lightly regulated information service.

The proposal would designate broadband transmission as a telecommunications service, which, as with telephone service, would make it subject to stricter regulation.

The commission has said it intends to exempt broadband service from most of the regulatory options it has under the stricter designation, keeping only those regulations that are necessary “to implement fundamental universal service, competition and market entry, and consumer protection policies.”