Updated from July 5

Clearwire netted a $600 million investment from Intel's ( INTC) Intel Capital and says it has agreed to sell a wireless broadband unit to Motorola ( MOT).

The company also withdrew a planned $400 million initial public offering it originally registered in May.

In addition to selling its NextNet Wireless business to Motorola, the agreement makes Motorola a key supplier of network infrastructure to Clearwire.

The closely-held Craig McCaw start-up has plans to use a not fully standardized technology known as Worldwide Interoperability of Microwave Access, or WiMax, to provide high-speed wireless service.

"Wi-Fi has become an essential part of people's lives. WiMAX is next. It is rapidly moving from a technology initiative to real deployments," Intel Mobility chief Sean Maloney says in a press release Wednesday.

The Kirkland, Wash.-based tech shop has WiMax service in 27 markets, largely in the Northwest and Mid-Atlantic. The company has about 18,000 subscribers in the U.S. and 11,500 in Belgium and Ireland.

Clearwire holds licensed radio spectrum in the 2.4 gigahertz to 2.6 gigahertz range and delivers fast mobile connections over a much broader territory than technologies like WiFi, with their hot-spot limitations.