Leap Wireless International will begin offering the iPhone through its Cricket Communications division, becoming the first prepaid carrier in the US to sell Apple’s smartphone.

The company has entered into a three-year, $900 million purchase commitment with Apple to offer the iPhone 4S and iPhone 4, according to a filing yesterday.

Leap is offering the iPhone for $500 and will start selling the devices on June 22 with a $55-a-month unlimited talk, text and data plan.