In a 3-2 party-line split, the Federal Communications Commission voted Thursday to move ahead with rules that could allow Internet service providers to charge more for faster content delivery but would also add protections for consumers.

Chairman Tom Wheeler formally unveiled a notice of proposed rulemaking, stressing the intention to “protect and promote the Internet as an open platform” by barring broadband providers from blocking content; requiring “commercially reasonable” arrangements for paid prioritization; enhancing transparency; and creating an ombudsman to watch out for consumers and small businesses.