The Federal Communications Commission approved a data roaming rule on Thursday that will allow consumers to access the Internet from their smartphones anywhere in the nation even if their carrier doesn’t have coverage in an area.

The rule requires that carriers with cell phone coverage allow other carriers to offer roaming services to their customers.

“The framework we adopt today will spur investment in mobile broadband and promote competition,” said FCC Chairman Julius Genachowski. “It will ensure that rural and urban consumers have the ability they expect to use their mobile phones throughout the nation for voice calls or data — like e-mail or mobile apps.”

Verizon Wireless, the nation’s biggest wireless carrier, immediately opposed the order, saying that the FCC doesn’t have the authority to regulate Internet service providers. Verizon Communications, the parent company of Verizon Wireless, has sued the FCC in federal court for Internet access rules known as net neutrality. The company argues that the U.S. Court of Appeals for the District of Columbia ruled that the agency’s doesn’t have jurisdiction over broadband services.

When asked if Verizon would sue the FCC to overturn the data roaming order, spokesman Ed McFadden said, “We are going to review the order, and we’re keeping our options open.”

The order was passed in a 3-to-2 vote, with Democrats in favor and Republican commissioners opposed.

In an annual report, the agency for the first time determined that the wireless industry isn’t competitive enough. That concern has been cited by smaller carriers as a reason to block AT&T’s proposed merger with T-Mobile.

Rural carriers such as Cellular South have argued that they are at a competitive disadvantage to the national major carriers because they can’t offer users full Internet access in the nation. The rules would require carriers to work out reasonable negotiations for roaming partnerships, and the FCC said it would punish companies that delay deals or “negotiate in bad faith.”

“The FCC must be congratulated for taking this action despite the opposition of the two largest U.S. wireless carriers who have lobbied against this pro-consumer, pro-competitive item,” said Vonya McCann, Sprint Nextel’s senior vice president of external affairs. “With AT&T’s proposed acquisition of T-Mobile and the corresponding threat it poses to continued wireless competition, it is absolutely critical that the FCC take steps to promote competition and level the playing field.”