WiMAX users in the US will be getting their 4G wireless services not from Sprint -- and not from the "old" Clearwire -- but from a combined entity known as "New Clearwire."

The long sought after FCC approval of a $14.5 billion WiMAX merger between Sprint-Nextel and Clearwire opens the door to the start of nationwide 4G services to be offered through a new provider called New Clearwire, an entity that will compete with 4G LTE services from Verizon Wireless and AT&T.

But although AT&T had tried last summer to squelch the merger of Sprint and Clearwire's WiMAX networks, WiMAX now looks virtually certain to get out the door first with 4G services in multiple cities.

"Today's action paves the way for Sprint, Clearwire, and other investors to partner to deploy a nationwide wireless broadband network in the 2.5 GHz band, something that these companies have not been able to accomplish individually," contended FCC Commissioner Robert McDowell in a statement on Tuesday.

With the WiMAX licenses of Sprint and Clearwire about to be transferred to New Clearwire, Sprint will be freed up to focus more on network upgrades, customer service, and other areas of its core businesses that have demanded attention.

Completion of the WiMAX deal has taken almost 18 months, though. Sprint and Clearwire first announced intentions to team up on a WiMAX offering called Xohm back in mid-2007. But then, in November of that year, a financially strapped Sprint canceled those initial plans.

In May of this year, however, the two wireless companies renewed their WiMAX relationship in a big way, combining their WiMAX holdings in a new entity partly funded by $3.2 billion in investments from Google, Intel Capital, Comcast, Time Warner, and Bright House Networks.

For its part, Sprint recently launched its first commercial WiMAX services in sections of the city of Baltimore, MD.

Meanwhile, Clearwire has been conducting a small beta test of its own WiMAX offering in Portland, OR, with intentions to launch commercial services in Oregon, Nevada, Georgia and Michigan in 2009.

"[But] 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," a Clearwire spokesperson told BetaNews back in July.

Like Verizon in its $28.1 billion merger with Alltel, also approved by the FCC on Tuesday, Sprint had to make some concessions in getting the merger with Clearwire cleared by the federal agency.

The FCC has now required Sprint to phase out its requests for federal high-cost universal service support over the next five years, as well as to use counties for measuring compliance with the agency's E911 location accuracy rules for handset-based technologies.