Sprint is buying U.S. Cellular markets in the Midwest for $480 million to boost its network capacity in that region.

Sprint Nextel Corp., the third-largest U.S. cellphone carrier, said Wednesday that it is buying spectrum and 585,000 customers in Illinois, Indiana, Michigan, Missouri and Ohio. That covers about 10 percent of U.S. Cellular's customer base and includes its key Chicago and St. Louis markets.

The acquisition should give a needed boost to the Overland Park, Kan.-based company's network. Sprint doesn't have as much available spectrum, or space on the airwaves, as the larger carriers do. That holds back its network speeds somewhat.

Chicago-based U.S. Cellular Corp. said the sale will help it focus on its strongest markets.

The acquisition, which remains subject to regulatory approval, is expected to close in the middle of next year.

Also on Wednesday, U.S. Cellular said its third-quarter net income dropped 43 percent, as the company subsidized sales of new smartphones.

U.S. Cellular earned $35.5 million, or 42 cents per share, down from $62.1 million, or 73 cents per share, in the same quarter last year. Revenue rose 3 percent to $1.14 billion.

Sprint shares fell 4 cents to $5.69 in premarket trading. U.S. Cellular Corp. shares were unchanged from Tuesday's close of $39.02.