Clearwire operates the WiMax network that Sprint uses for its 4G plans, and it continues to sell its own services on the network under the Clear brand. But financial woes have already cut into Clearwire's retail business, and though Clear is a relatively small player in the mobile broadband business, some analysts say competing with Sprint hasn't helped relations between the companies. Some have predicted Clearwire will its retail business.

On Monday, Clearwire streamlined its plans to offer only no-contract, unlimited WiMax data services starting at US$50 per month. The company now offers the 4G Mobile and the 4G Home plan, which are offered with different types of modems, and short-term plans for weekly, daily and two-hour access. There are also bundles of mobile and home plans. Subscribers to the monthly plans are charged each month but can cancel at will, with no term commitment.

The company has also stopped selling new USB modems and standalone hotspots that include 3G radios. That means new Clearwire subscribers will only be able to get service in areas where the WiMax network is deployed. Clearwire previously had sold some gear that could access Sprint's 3G network, which has a lower top speed but is more widely available. Sprint has a nationwide 3G network, while the Clearwire network reaches about 130 million U.S. residents. Clearwire spokesman Mike DiGioia said the phase-out of dual-mode devices has been a process going on since April.

Existing Clearwire subscribers can keep their current service plans and continue using their dual-mode devices, DiGioia said.

In addition to the other changes, Clearwire is no longer offering leased equipment but only selling its modems, and there are no credit checks before signing up for service.