Last month, Clearwire Chief Executive William Morrow said that the Kirkland broadband wireless provider was amenable to switching the company's network infrastructure from WiMax to Long Term Evolution (LTE).

"We'll do what's right for the business," Morrow told Dow Jones. "Whether it's LTE, WiMax, future technology X, it doesn't matter to me."

But that switch won't be happening in the near-term. Unstrung -- citing a SEC filing from August -- reports that Clearwire is locked into an agreement with Intel to support WiMax until 2011.

The filing notes:

Other competing technologies, including other 4G or subsequent technologies, will be developed that may have advantages over mobile WiMAX, and operators of other networks based on those competing technologies may be able to deploy these alternative technologies at a lower cost and more quickly than the cost and speed with which we deploy our network, which may allow those operators to compete more effectively, assuming they have adequate spectrum resources, or may require us to deploy such technologies when we are permitted to do so.

The Intel Market Development Agreement runs through November 28, 2011. Unstrung reports that Clearwire could consider changing its network since vendor support for WiMax technologies may prove to be uncertain.

Clearwire has said that it plans to roll out its 4G WiMax network in 25 networks by the end of this year, including Seattle, Charlotte and Chicago.

In other news, Clearwire said that Alvarion and ZTE Corp. will support the company's launch of WiMax in Spain next year. The company plans to launch in Malaga and Sevilla.