US mobile operator Sprint Nextel has disappointed the WiMAX community with the news that it will delay the commercial launch of its eagerly-anticipated “Xohm” WiMAX network. The company was scheduled to launch the service this month.

Sprint has not rescheduled a new date but many at this week’s CTIA show believe this summer is a more likely timescale. The company was expected to make a major splash at the event with the service, but instead only revealed details of a new WiMAX-enabled handset.

The delay is said to be largely because of problems setting up the internet links behind the WiMAX part of the network. Barry West, CTO of Sprint and head of the Xohm business unit, said. “What’s holding us back is simply the logistics of building the network, and specifically the problem of provisioning backhaul connections to the internet.”

According to a report from Dow Jones, the company’s WiMAX project (thought to be costing US$5 billion) has been a source of criticism from some on Wall Street, who would prefer the company to focus on its core mobile business. Meanwhile, Sprint continues to negotiate with several cable companies to provide additional funding for the rollout and to create a separate joint-venture with Clearwire, the specialist WiMAX company.

One industry watcher, Clint Wheelock, chief research officer at ABI Research, said, “The delay of Xohm’s commercial launch is a major blow for Sprint, and the storm clouds are only getting darker over the entire WiMAX sector.”

Sprint continues to run trial networks in Chicago and Baltimore-Washington. These networks, however, will remain employee test beds for the moment.