6:48 a.m. | Updated
Sprint Nextel has secured control of Clearwire, the wireless network operator that holds valuable spectrum, according to a regulatory filing on Thursday.
The filing shows that Sprint agreed on Wednesday to acquire the interests in Clearwire held by Craig O. McCaw's Eagle River Holdings. The transfer of Class A shares and Class B interests gives Sprint a majority stake of 50.8 percent of Clearwire.
The agreement simplifies a relationship with Clearwire that has complicated Sprint's attempts to overhaul its network. It comes as Sprint is preparing to sell a 70 percent stake in itself to the big Japanese cellphone provider and Internet company SoftBank, for $20.1 billion.
Taking control of Clearwire was not a necessity for the completion of the SoftBank transaction, which is expected to close by the middle of next year, pending regulatory approval. And it may not consist of buying out other investors' stakes in the company altogether: one person briefed on the matter suggested that Sprint could buy the voting rights of some of its partners.
But Sprint and SoftBank have also not ruled out pursuing a full acquisition after their own deal closes.
Shares in Clearwire rose 1.7 percent, to $3, in premarket trading on Thursday.
Clearwire, founded in 2003 by Mr. McCaw, a pioneer in the wireless services industry, already handles some data traffic for Sprint customers. But it has long faced financial difficulty, requiring several cash infusions from outside investors.
While the company focused on a wireless data standard that has been supplanted by Long Term Evolution, or LTE, it holds valuable spectrum that Sprint and its prospective new owner covet.
That wireless resource could be used to develop Sprint's LTE data network, which would support newer devices like the Apple iPhone 5 and various Android-based products.
Building out that network is among the most important goals SoftBank has for Sprint. SoftBank's chief executive, Masayoshi Son, has devised a strategy revolving in large part around building the same sort of high-speed data infrastructure he is creating in the Japanese market.
Mr. Son believes having a reliable and fast network would allow Sprint to better take on the two major wireless service providers in the United States, Verizon Wireless and AT&T.
“U.S. citizens don't have this experience of high speed,†Mr. Son said on a conference call with analysts on Monday. “We're going to bring that to the States.â€
Through a number of investments, Sprint previously had about 48 percent of Clearwire, and the right to fill seven seats on the company's 13-member board. But without greater control over the wireless broadband provider, Sprint ran the risk of losing control of one of its most important partners.
A version of this article appeared in print on 10/18/2012, on p age B5 of the NewYork edition with the headline: Sprint Is Said to Be Seeking More Control of Clearwire.