BY PETER SVENSSON

AP Technology Writer

NEW YORK

The Verizon version of the iPhone 5, which went on sale Friday, came with an unexpected feature: It works on the network of AT&T and many other phone companies, as well as on Verizon's.

It's the first time Verizon, the country's largest cellphone company, has sold a phone that works on competing U.S. networks with no complicated hacking, or "unlocking," procedures.

Last year, the first shipments of the Sprint iPhone 4S were unlocked and worked on AT&T, but Sprint later issued software updates that turned off that capability.

Verizon Wireless spokeswoman Brenda Raney said Monday that Verizon does not plan to relock the iPhone 5.

The feature may mean little initially to most buyers, since they sign up for two years of Verizon service when buying the phone. But it does give them the option to switch carriers when the contract expires, or they can sell the phone to someone who plans to use it on a competing network. They also have the option of breaking the contract, paying an early termination fee, and signing up for cheaper service--the Verizon iPhone 5 even works on prepaid service plans.

Verizon and Sprint do "unlock" other phones on request, but only for use on non-U.S. networks. They do so to let travelers save money by using local SIM cards and accounts when overseas.

Even unlocked, Verizon iPhones are tied to Verizon's network: it's the only one that can provide them with "4G LTE" data speeds. The Verizon iPhone 5 can access AT&T's non-LTE "4G" network, which has slightly lower speeds.

T-Mobile USA, the country's fourth-largest phone company, has a network that's compatible with the Verizon iPhone 5 for voice calls and low-speed data.