FCC commissioners yesterday granted regulatory approval to the merger of Sprint and Nextel Communications to form the third-largest nationwide wireless carrier.

With the approval, all spectrum licenses held by Nextel will be transferred to Sprint. The merged company will not have a dominant position in any market, so the commission opted not to require any divestitures. However, the regulatory approval was conditioned on the merged company spinning off Sprint’s local wireline holdings with an “equitable debt and asset allocation” and meeting benchmarks for providing broadband wireless services using the company’s vast spectrum holdings in the 2.5 GHz band.

“When we complete the merger, Sprint Nextel will have unmatched wireless capabilities and a global IP network to provide consumers with high-value, integrated communications solutions to meet their needs,” Nextel President and CEO Tim Donahue said in a prepared statement. “We are eager to get started.”

When the deal is completed, the merged company will be known as Sprint Nextel and will be traded on the New York Stock Exchange under the ticker symbol “S.” Sprint’s local wireline holdings will be spun off to form a new company, LTD Holding Company.

The 2.5 GHz conditions require Sprint Nextel to serve 15 million customers with wireless broadband services using the spectrum within four years. Two years later, the merged company will be required to serve 30 million broadband customers using the 2.5 GHz airwaves.

All four commissioners supported the merger, but Commissioner Michael Copps expressed concern that consolidation in the wireless industry has left four nationwide carriers where there were six just two years ago.

“While I am sensitive to the arguments that six national competitors could not have been forever sustained in the wireless market, I am also concerned about what this substantial reduction in the number of competitors may mean for wireless consumers,” Copps said in a prepared statement. “The FCC will have to take a hard look at whether we have gone about as far as we can go.”