Cable operator Comcast has begun reselling Clearwire’s mobile WiMAX service in Portland, Ore., under the brand High-Speed 2go. Comcast is the first Clearwire investor to resell the service.

The mobile WiMAX service will be sold in a bundle with at least one of the Comcast’s Internet, phone or television products. High-Speed 2go will be available in Atlanta, Philadelphia and Chicago by year-end.

Cable operators are under increasing competitive pressure from carriers offering similar bundles comprised of wireline, wireless and Internet. AT&T and Verizon Communications recently turned up the heat with their respective fiber-optic services, U-Verse and Fios. Those bundles are nearly identical to those offered by cable companies and feature a package of digital television, phone, high-speed Internet and wireless.

4G has the potential to keep cable companies relevant and competitive as teleco’s encroach into their territory. “Comcast does not want to get into the wireless space, but they have to because their major competition is,” says telco analyst Jeff Kagan. “If they don’t, they’ll lose business. It’s just that simple.”

Kagan lives in Atlanta, where Clearwire recently launched its 4G Clear service. Although there have been some negative reviews of the service, Kagan found that the connection was fast and worked well.

However, Kagan predicts that the company’s existing customers likely will choose either wireless or wireline Internet, not both, minimizing the positive impact of the service on Comcast’s bottom line. He also expects that customers currently using carrier’s nationwide Internet cards will stick with them.

“Basically, this is going to compete with the DSL services and the cable company service. It’s not really going to compete with the wireless Internet service that you buy from your cell phone company,” he says. “It’s not like this is going to mean more business for the cable companies.”