WASHINGTON — The Federal Communications Commission voted on Thursday to dismantle landmark rules regulating the businesses that connect consumers to the internet, granting broadband companies power to potentially reshape Americans’ online experiences.

The agency scrapped so-called net neutrality regulations that prohibited broadband providers from blocking websites or charging for higher-quality service or certain content. The federal government will also no longer regulate high-speed internet delivery as if it were a utility, like phone services.

The action reversed the agency’s 2015 decision, during the Obama administration, to better protect Americans as they have migrated to the internet for most communications.

Ajit Pai, the chairman of the commission, said the rollback of the rules would eventually help consumers because broadband providers like AT&T and Comcast could offer people a wider variety of service options. Mr. Pai was joined in the 3-to-2 vote by his two fellow Republican commissioners.

“We are helping consumers and promoting competition,” Mr. Pai said in a speech before the vote. “Broadband providers will have more incentive to build networks, especially to underserved areas.”