In a major deal that could launch the next generation of wireless broadband, Sprint Nextel and Clearwire are close to announcing a $12 billion joint venture to build a nationwide WiMax network offering superfast wireless service for cell phones and laptops.

The partnership, which includes $3.2 billion in financing from Comcast, Intel, Google, and Time Warner Cable, could be announced as early as Wednesday, according to the Wall Street Journal, which first reported the pact. Under the terms of the deal, Sprint will merge its broadband business with Clearwire, the Kirkland, Washington, broadband company founded by cell-phone pioneer Craig McCaw.

With such powerful backers, the deal suggests that WiMax—long touted as the successor to WiFi—could be finally poised for widespread adoption throughout the United States.

"This is a big deal because it significantly increases the likelihood of widespread deployment of WiMax," said Rob Enderle, president of Silicon Valley-based tech advisory firm Enderle Group.

The joint venture marks the culmination of months of complex on-again, off-again negotiations between the parties and provides a much-needed lift to the WiMax standard, a still unproven technology that backers say offers speeds five times faster than traditional wireless networks.

The deal is a major boost for Sprint Nextel, which lost one million phone subscribers last year and has been outperformed in the mobile space by competitors Verizon and AT&T, which are pursuing their own next-generation wireless standard, known as Long Term Evolution, or LTE.

"Without this deal, it was unclear whether Sprint would be too distracted to make WiMax happen and whether it could independently raise the billions needed," said Glenn Fleishman, editor of WiMax Networking News. The new joint venture has "a real chance to push out something that's as fast as today's typically higher-end cable and DSL."

"While metro areas will get the focus, there are tens of millions of people in rural areas and exurbs that could be served by a very cheap WiMax rollout by Sprint and Clearwire, who currently have dial-up or satellite," Fleishman added. "This is a huge amount of money that's left on the table by incumbent wireline providers."

By providing financing, the two cable companies and Google are positioning themselves to be key players in the rollout of the network. Intel has long supported the WiMax standard. The new company, which will keep the Clearwire name, will receive $1.05 billion in financing from Comcast; $1 billion from Intel; $550 million from Time Warner Cable; and $500 million from Google.

"For the cable companies, this could solve the 'last-mile' problem because it's much easier to beam the signal into homes than to have to install new cable," Enderle said. As for Google, "the company doesn't care who owns the network, just as long as they can send their content over it."