WASHINGTON — The Justice Department on Thursday effectively gave Verizon Wireless the go-ahead to buy Alltel in a $28 billion deal that would create the nation's largest wireless carrier.

Verizon Wireless, a joint venture between Verizon Communications and Britain's Vodafone Group, already agreed to the government's condition it sell assets in 22 states.

"We're pleased that the Department of Justice has granted approval," said Robin Nicol, a Verizon Wireless spokeswoman. "It's another step in the right direction."

The Federal Communications Commission is slated to vote on the merger Tuesday.

Andrew Moreau, an Alltel spokesman, said the company is "looking forward to the FCC meeting scheduled for next week."

Justice Department lawyers joined seven states in a lawsuit filed Thursday to block the merger, but also filed a proposed settlement that would require Verizon Wireless to divest assets in 100 markets. Without that action, the Justice Department said, the deal would hurt competition, drive up consumer prices and likely produce a lower-quality network.

Under terms of the deal, Verizon Wireless plans to buy Little Rock, Ark.-based Alltel for $5.9 billion plus the assumption of $22.2 billion in debt.