Apple sold out of its latest smartphone, with more than 5 million units of the iPhone 5 sold in the three days since it hit stores, the company said today.

The early total blasted past sales of the iPhone 4S, which sold more than 4 million units in its first weekend after Apple introduced it in October 2011.

Apple said while the majority of iPhone 5 pre-orders have been shipped to customers, many were scheduled to go out in October.

"While we have sold out of our initial supply, stores continue to receive iPhone 5 shipments regularly and customers can continue to order online and receive an estimated delivery date," Apple chief executive Tim Cook said in a statement.

Apple signaled last week that pre-orders outstripped initial supply and that many p hones would not be available until October.

Still , there we re concerns Apple may not be able to produce the i Phone 5 fast enough to meet demand a round the world.

"They may not be able to build them fast enough to hit their targets," said Colin Gillis, a research analyst with BGC. "The reality is if they can't build (fast enough), any hiccup is going to be a negative."

On Friday, fans lined up at stores in cities around the world to get their hands on the new phone, which is thinner and lighter and has a bigger screen.

Shares of Apple were down 1.2 per cent at $691.54 in early trading.

Reuters