Verizon Wireless

is paying a steep price for growth.

The No. 2 cell phone service says it has reached an agreement with

NextWave

to buy $3 billion in radio wave licenses covering 23 cities. The deal comes just weeks after Verizon Wireless -- a joint venture between

Verizon

(VZ) - Get Report

and

Vodafone

(VOD) - Get Report

-- closed a $930 million wireless spectrum purchase also from NextWave, which is in Chapter 11.

Verizon Wireless says it plans to pay for the new spectrum with money from its operations and does not anticipate the need to seek additional financing. The move shows that Verizon Wireless is confident that it can continue its brisk business pace, but some industry observers question how long the run will last.

Subscriber growth and soaring revenue has been the bright side of Verizon's otherwise bleak and shrinking local phone business. The company added 1.58 million net retail customers last quarter, giving Verizon a total of 42.1 million customers.

With the most recent deal, Verizon Wireless adds 10-megahertz and 20-megahertz air waves in the 1.9 gigahertz radio frequency. The largest capacity will be added in New York, Los Angeles, Baltimore and Boston. Verizon Wireless' previous spectrum addition was 10 megahertz of 1.9 gigahertz air waves in New York.

Overall, the new licenses add radio wave capacity to cover a population of 73 million people in 22 existing Verizon Wireless cities, and expand the company's network reach to Tulsa, Okla., where it previously had no wireless system.

The deal needs regulatory approval and an OK from U.S. Bankruptcy Court if the NextWave reorganization plan is accepted. Verizon Wireless expects to close the deal by the middle of next year.