Dish Network Corp., the satellite-TV company controlled by Charlie Ergen, made an unsolicited $25.5 billion offer for Sprint Nextel Corp., topping a Softbank Corp. bid for the third-largest U.S. wireless carrier.

Sprint investors would get $7 a share, including $4.76 in cash, a stake representing about 32 percent of the combined company, Englewood, Colorado-based Dish said today. While the offer is 13 percent above Sprint's April 12 closing price, the stock climbed above $7 in New York trading today, suggesting that investors expect the bidding to go higher.

The bid represents that most aggressive move yet by Ergen to break into the wireless-phone market, part of his strategy to decrease reliance on the slowing satellite industry. Acquiring Sprint would mean outdueling Softbank, Japan's third-biggest mobile-phone operator, which agreed in October to pay $20 billion for a 70 percent stake in the carrier.