Apple will start selling unlocked iPhones from Wednesday, said a report based on leaks.

The GSM iPhone which has been locked to AT&T and CDMA iPhone since the time of its launch in the United States will now allow users to use a SIM card from any GSM carrier.

ChronicWire revealed in Twitter, ‘Unlocked iPhones headed to Apple Stores for Wednesday: MC603 (16GB, Black) MC604 (16GB, White) MC605 (32GB, Black) MC606 (32GB, White)’

ChronicWire had earlier reported that Apple was planning to release MacBook Air on Wednesday, but later it confirmed that it’s not the MacBook Air, it’s the unlocked iPhone that is going to be on sale.

Apple is expected to sell the unsubsidized factory unlocked iPhone 4 for $599 (16 GB model) and $699 (32 GB model). Despite the high price tag, factory unlocked iPhones are popular among international travelers who may need to frequently switch SIM cards to avoid the exorbitant international roaming charges.

However, TipB points out that T-Mobile users may not get excited as the iPhone would most likely have no support for T-Mobile’s 3G network frequencies in the U.S.

iPhone5 which is expected to be released in the next few months is rumored to be having T-Mobile's 3G network support.