WASHINGTON— Federal regulators are signing off on Verizon Wireless’ planned $28 billion purchase of Alltel Corp. The deal will create the nation’s largest wireless carrier.

With partial dissents by the two Democrats on the five-member panel, the Federal Communications Commission decided Tuesday to allow Verizon Wireless to move ahead with the deal for Alltel. Verizon is paying $5.9 billion and assuming $22.2 billion of Alltel’s debt.

The FCC is attaching several conditions to the deal, including a requirement that Verizon Wireless honor Alltel’s existing roaming agreements for four years.

The Justice Department approved the deal last week after Verizon agreed to sell assets in 22 states.

Verizon Wireless is a joint venture between Verizon and Vodafone Group PLC.