In a bid to quash a proposed merger between Sprint-Nextel and Clearwire around WiMAX, AT&T has now submitted a petition to the FCC.

Sprint announced in May that it would renew its efforts to partner with Clearwire to bring together both companies' WiMAX holdings to build a nationwide broadband wireless network. Valued at about $14.5 billion, the proposed network has financial backing from Intel, Google, Comcast, Time Warner, and Bright House Networks.

But the FCC must okay the plan before it is complete. AT&T has now filed a petition to the FCC claiming that Sprint and Clearwire "intend to compete with other national wireless providers -- including AT&T -- yet they fail to make the required showings necessary for the commission's review."

Even if the merger doesn't go through, however, AT&T could still stand to lose a lot of ground in 4G wireless broadband, since Sprint and Clearwire are each poised to deliver commercial services much faster.

Sprint, of course, already does compete with AT&T and Verizon in current 2G/3G wireless services, where it is lagging behind badly. Yet ironically, in the higher bandwidth 4G arena, Sprint holds a strong edge. In terms of actual deployments, WiMAX is generally regarded as years ahead of a rival technology -- Long Term Evolution (LTE) -- which is now in the process of adoption by AT&T, in addition to Verizon Wireless.

Meanwhile, Sprint has already announced testing with Samsung in the Washington, DC/Baltimore and Chicago areas, with plans for a commercial launch of WiMAX in Washington, DC by the end of 2008.

For its part, Clearwire is now conducting a small beta test of its WiMAX offering in Portland, OR, with intentions to launch commercial services in Oregon, Nevada, Georgia and Michigan in 2009, a company spokesperson told BetaNews earlier this month.

But, she added, "I would like to emphasize that while Clearwire and Sprint announced a transaction to merge our WiMAX businesses, the deal is still pending approval. Until the transaction is closed, we will continue to operate as separate companies and therefore our networks are separate as well."

In its recent petition, AT&T contended that, in filing their paperwork with the FCC, Sprint and Clearwire left out some of the spectrum they intend to use because it isn't operational yet.

But could this be more than simply sour grapes on AT&T's part? Implying a lack of fairness, AT&T said that when it purchased Dobson Communications last year, the FCC took a look at the account spectrum AT&T hadn't yet accessed.

Although the FCC approved AT&T's Dobson buyout last November, AT&T argues that the Sprint-Clearwire proposal would face tougher scrutiny if all of Sprint's and Clearwire's spectrum holdings got taken into account by the FCC.

Meanwhile, rural wireless operators are also fighting the merger, but on grounds that roaming might interfere with their own operations.

In a petition to the FCC through the Rural Cellular Association, the operators said that under these "unique circumstances there is a manifest need for the commission to recognize the impact of both transactions upon consumers and act to promote carrier-to-carrier network interoperability, including automatic roaming for voice and data, notably for wireless broadband services."

Also in the FCC filings, however, other groups -- including the Wireless Communications Alliance (WCA) and the Catholic Television Network -- are supporting the proposed Sprint-Clearwire merger.