CUPERTINO, California: Apple, the consumer electronics firm, sold more than 1.7 million units of its iPhone 4 in the first three days the product was on sale, a new record for the company.

Figures from the maker of the iPad and iMac showed the latest addition to its portfolio experienced greater demand than its predecessor, the 3GS, which shifted one million handsets in its opening 72 hours.

The iPhone 4 hit store shelves in the US last Thursday, while Apple also took advance orders for over 600,000 devices, ten times the amount posted by the 3GS.

"It's amazing how the fourth iteration of a product could generate the longest lines and the strongest sales yet," said Walter Piecyk, an analyst at BTIG Research.

Estimates from industry observers suggest Apple will ship approximately 36 million iPhones over the year to September, which would constitute an increase of 73% on an annual basis.

However, there have been complaints regarding widespread shortages and questions relating to poor reception if the iPhone 4 is held in a certain way.

AT&T, the exclusive service provider for the iPhone, is expected to sell its newest variant to walk-in customers in its stores from next Tuesday. 

Wal-Mart and Best Buy are already stocking the iPhone4, but many of their outlets have been unable to keep up with interest among shoppers.

The most recent offerings from Apple's rivals include the Motorola Droid X, which was unveiled at a press conference a day before the iPhone 4 launch.

Samsung's Galaxy S, which will be sold by three of the four national carriers in the US, is also hoping to enhance its position in this rapidly-growing smartphone sector.

Data sourced from Wall Street Journal; additional content by Warc staff