Sprint Wants To Buy Rest Of Clearwire To Speed 4G Buildout

The move came after the U.S. Federal Communications Commission approved new spectrum use to encourage 4G use. As well, Japan's SoftBank Corp. (TYO:9984) has bid $21 billion to acquire Sprint, and already given the Overland Park, Kan., company $3 billion in cash.

Shares of Clearwire, of Bellevue, Wash., surged another 15 percent Thursday after gaining 15 percent on Wednesday, valuing the company around $4.6 billion.

Sprint offered $2.90 a share for the 48 percent of Clearwire it doesn't already own. In Thursday trading, Clearwire shores rose to $3.16, up 41 cents.

Sprint, which had owned about 48 percent of the company, boosted its stake above 51 percent just after it received the cash from SoftBank. The SoftBank-Sprint deal, if approved, will take effect in mid-2013.

Sprint shares fell 2 cents to $5.64, after several analysts suggested the carrier might have to pay more for Clearwire, the second company invenrted by mobile phone Craig McCaw, whose McCaw Cellullar Corp. was acquired by AT&T Inc. (NYSE:T) and is the backbone of the No. 1 mobile network.

Walter Pieczyk, of BTIG Research, told clients that the other shareholders, including Intel Corp. (NASDAQ:INTC)  and Google (NASDAQ:GOOG) of Clearwire might want more cash for their shares, despite McCaw's sale of his interest to Sprint. He got $2.97 for his shates.Based on current spectrum sales, that could be as much as $5 a share, he estimated.

At Wells Fargo, analyst Jennifer Fritzche also suggested Sprint would have to pay more.