T-Mobile USA is looking at possible joint ventures for additional spectrum.

Several news sources reported the following comments by T-Mobile USA CEO Robert Dotson, who was speaking at a recent investor conference: “We continue to look at JV opportunities for additional spectrum ... there are a number of different options we look at, [we] have been talking with cable companies, with Clearwire.”

Dotson provided no further details.

T-Mobile is in the process of building an advanced 3G network, using HSPA+ technology, and though it will eventually move to 4G, has yet to commit to any specific 4G strategy.

A deal with Clearwire would give T-Mobile immediate access to 4G spectrum and services. T-Mobile could presumably re-brand Clear WiMAX just as Sprint, Comcast and Time Warner Cable do.

The reference to the cable networks could be to Clearwire, as Comcast, TWC and Bright House are all investors in Clearwire.

It could also be a reference, however, to the AWS spectrum held by some of the cable partners in SpectrumCo, a partnership among Comcast, TWC, Cox and Sprint.

Comcast and TWC have never used their spectrum allowances. T-Mobile’s spectrum is also in the AWS band. T-Mobile could presumably conduct a build-out using its potential cable partners’ spectrum holdings.

Dotson was also reported to have dismissed persistent rumors that T-Mobile parent Deutsche Telekom might buy Sprint and combine the two. Despite the rumors, this strikes many as unlikely, as T-Mobile’s network uses GSM technology, while Sprint uses CDMA; the combination would be technologically awkward at best.