Before the end of the year, Clearwire and Sprint plan to launch 4G wireless service in the nation’s two largest metro areas—New York City  and Los Angeles —as well as San Francisco,  the carriers announced yesterday. Time Warner Cable joins the partners in offering the service in New York, which will be available November 1, and Comcast will join in offering the service in San Francisco beginning in late December. Service in Los Angeles is scheduled to launch December 1.

Just a few months before Clearwire and Sprint merged their 4G networks in late 2008,  Clearwire talked about offering a five-product suite of services including residential voice and broadband, mobile voice and broadband and mobile entertainment.  Yesterday’s announcements, however, focused only on mobile broadband and entertainment.

Customers will be able to “increase their mobility and productivity in many ways: from instantly downloading large files to get work done on the run, to browsing the web just like at home from across the city, or watching online videos and movies nearly anywhere around town,” the announcements said.

Both Clearwire and Sprint plan to provide dual-mode 4G/3G devices for use with service in the new markets, enabling customers to use Sprint’s 3G service where 4G is not available. Comcast said it will market the 4G service as part of a “Fast Pack” that includes wired and wireless Internet connectivity together.  

Although Clearwire already offers 4G service in 56 U.S. markets, many of those are smaller markets such as Boise, Idaho and Wichita Falls, Texas. The carrier also serves close to a dozen NFL markets, including the nation’s third and fourth largest, Chicago and Houston. Clearwire said yesterday that it also expects 4G service to be available in “other major metro areas such as Denver, Miami, Cincinnati and Cleveland” before the end of 2010.

The race is on as Clearwire/Sprint and its partners try to launch as many markets as possible ahead of Verizon’s pending 4G LTE launch.