(AP)—Sprint says it's reached a deal to buy U.S. Cellular markets in the Midwest for $480 million to boost its network capacity as it upgrades its network.

Overland Park, Kan.-based Corp. says it's buying spectrum and 585,000 customers in Illinois, Indiana, Michigan, Missouri and Ohio.

That's 10 percent of U.S. Cellular's customer base and includes the Chicago company's Chicago and St. Louis markets.

The acquisition is expected to close in the middle of next year.

Sprint shares are down 6 cents, or 1 percent, to $5.67 in premarket trading. U.S. Cellular Corp. stock is unchanged before the opening bell.