NEW YORK, USA: Apple Inc had sold 1.7 million units of the iPhone 4 worldwide by Saturday, June 26, its most successful product launch yet, the company said on Monday. The smartphone was launched internationally on Thursday.

In a statement, chief executive Steve Jobs apologized to "customers who were turned away" because the company did not have enough supply.

"This is the most successful product launch in Apple's history," Jobs said.

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Apple did not say whether the figure included pre-orders made on the company's website and in stores before the phone's official June 24 store launch.

AT&T Inc is the exclusive US provider for iPhone.