Oct. 26 (Bloomberg) -- Clearwire Corp, the money-losing wireless broadband provider, surged 20 percent after partner Sprint Nextel Corp. said the two companies are negotiating to extend a network-sharing agreement beyond 2012.

Sprint may use Clearwire's network to handle traffic from customers using Long-Term Evolution, or LTE, technology beginning in 2013, Sprint Chief Executive Officer Dan Hesse said on a conference call today. The talks are continuing, though a deal isn't completed, he said.

Sprint is 'making very good progress on the technical front with Clearwire,' Hesse said on the call.

Sprint said this month that it would stop selling devices that use WiMax, Clearwire's current technology, at the end of 2012, signaling the companies' partnership may end at the end of next year. Clearwire, which is majority-owned by Sprint and gets most of its revenue from the company, fell 32 percent that day.

Clearwire is planning to shift to LTE technology and needs almost $1 billion to make the transition. Sprint hasn't made any agreement to help finance Clearwire's LTE expansion, the company said.

Clearwire, based in Kirkland, Washington, rose to $1.96 at the close in New York. The stock has lost 62 percent this year.

To contact the editor responsible for this story: Peter Elstrom at pelstrom@bloomberg.net