Cupertino, Calif. — Apple has officially started selling an unlocked iPhone 4, CNET reported Tuesday.

The multi-billion dollar company has listed both a 16GB and 32GB unlocked version of the smartphone on their online store, retailing at $649 for 16GB and $749 for 32GB.

Apple’s decision to start selling unlocked versions of the phone stemmed from users who “prefer to use a local carrier when traveling abroad,” or for those who prefer not to have a multi-year service contract, the company wrote on its device’s product page.

“It arrives without a micro-SIM card, so you’ll need an active micro-SIM card from any supported GSM carrier worldwide,” Apple said.

The unlocked phone will only be available to iPhone 4 owners on AT&T and T-Mobile in the U.S., and via GSM carriers worldwide.

Related Links: (CNET) (Apple Store: unlocked iPhone 4)