By Sam Oliver

Published: 12:05 PM EST (09:05 AM PST)

AT&T, the exclusive carrier of the iPhone in the U.S., touted on Monday that a new third-party test found its network is 60 percent faster than competitor Verizon.

AT&T on Monday announced the results of the testing from Global Wireless Solutions Inc. Though the carrier did not specifically name Verizon, it noted that the "largest competitor by subscriber count" has a network 60 percent slower than AT&T's. Verizon is the largest wireless carrier in the U.S. in terms of subscribers, while AT&T ranks a close second.

The third-party test also found that the nearest competitor in terms of wireless speed was 20 percent lower than AT&T's network on average nationally. AT&T's press release did not indicate whether T-Mobile or Sprint was the next-fastest provider.

AT&T noted that it has invested nearly $6 billion in wireless initiatives over the first three quarters of 2010. That's a 55 percent increase over the same period in 2009.

"We're very pleased with the nationwide results of GWS drive testing, which demonstrate that we're delivering a superior mobile broadband experience on a nationwide basis," said John Donovan, AT&T's chief technology officer. "Our top priority for the weeks and months to come is to continue our focus on network enhancements and improvements to ensure continued access to fast mobile broadband speeds and reliable voice service."

The GWS test compiles wireless network performance results over 950,000 road miles in more than 400 U.S. markets. The testing area represents about 88 percent of the U.S. population.

AT&T boasted that its network allows customers to download a 40 megabyte MP3 album more than a minute faster than the next-fastest, unnamed network. AT&T's speeds would also allow an 80 megabyte video to be downloaded about two minutes faster.

The GWS tests also found that 98.59 percent of voice calls on AT&T's network were completed without interruption. The industry's best score, again from an unnamed carrier, had a better score by about one tenth of one percentage point, or one call in 1,000.

AT&T will be able to tout its network speed against Verizon in the first quarter of next year, when the iPhone is expected to be available on both carriers after Apple releases a CDMA version of its smartphone. Numerous mainstream media outlets have said that Apple is preparing for an early 2011 launch of the Verizon iPhone.

AT&T's HSPA+ high-speed network is scheduled to reach more than 250 million Americans by the end of this year. It offers a theoretical download speed of up to 14.4Mbps.