Windstream Corp. on Tuesday said it will buy Iowa Telecommunications Services Inc. (IWA) in a deal worth $1.1 billion, adding to its collection of local-phone properties in the Midwest. Under the agreement, Little Rock, Ark.-based Windstream plans to issue 0.804 shares and $7.09 in cash for each share of Iowa Telecom. Based on Monday's closing prices of both companies, the purchase equals about $16.14 per Iowa Telecom share and reflects a 26% premium. Shares of IWA are up 25% to $15.93 on massive volume.