AT&T is finally going after Sprint's WCS spectrum holdings for its own 4G LTE purposes.

Fierce Wireless reports that AT&T Inc. (NYSE: T) has filed with the Federal Communications Commission (FCC) to purchase Sprint Corp. (NYSE: S)'s 19 WCS licenses.

It has long been expected that AT&T could go after Sprint's 2.3GHz spectrum holdings. Sprint holds an average of 1 MHz or more of the spectrum across top markets in many of the southern US states. (See Sprint Could Make Millions Selling WCS to AT&T.)

In the summer of 2012, UBS AG analyst John Hodulik suggested that Sprint could make $130 million by selling its WCS licenses to AT&T. Ma Bell has made similar deals with Comcast Corp. (Nasdaq: CMCSA, CMCSK) and Horizon Wi-Com. It got the bulk of the licenses by acquiring NextWave. (See AT&T to Buy NextWave for 'Alternative' 4G.)

AT&T got approval from the FCC to use the spectrum late in 2012. Executives have said that it will go into commercial service in 2015. (See AT&T Gets WCS Approval, Adds 4G Markets.)

— Dan Jones, Mobile Editor, Light Reading