The FCC has given the green light for Verizon to sell some of its Alltel assets in mainly western states to AT&T for $2.35 billion two months after the Department of Justice approved the deal in April.

The divested assets cover 1.6 million subscribers across 18 states, including almost all of Montana and Wyoming, and portions of California and Arizona.

AT&T will launch its wireless service on a market-by-market basis over the next year as it works to integrate its network with Alltel’s technology. The carrier says it has no immediate plans to change customers’ phone numbers, rate plans, network coverage, customer service contacts or processes for making monthly bill payments. AT&T is also offering Alltel customers a device comparable to their existing handset at no additional cost during the network integration.

FCC Commissioner Michael Copps called the divesture an important step to restore competitive balance in rural areas of the western United States. “Absent these divestitures, consumers in large parts of the country would have inevitably experienced less competition, higher prices and lower quality of service,” he said.

The FCC’s approval of the sale to AT&T is the final chapter of Verizon’s $28.1 billion acquisition of Alltel, which made it the largest wireless operator in the United States. Verizon was required by federal regulators to divest 105 markets in order to pass anti-trust measures.

In addition to the sale of 79 markets to AT&T, Verizon sold 26 of its markets to Atlantic Tele-Network for $200 million, nearly tripling Atlantic’s subscriber base. The deal with Atlantic closed in April after the FCC approved the sale.