Apple will sell 4.47 million iPhone 3Gs in the current quarter, according a projection issued Wednesday by analyst Gene Munster of the merchant bank Piper Jaffray.

Munster, who is known to be extremely bullish on the sales prospects for Apple's hit communications device, had previously forecast iPhone's fourth quarter sales at 4.1 million.

But he revised his estimate after data teams spent 25 hours in Apple stores across the US over the past two weeks and discovered that each store was selling an average of 95 phones per day. Also bumping up the estimate was an Apple report that it sold 1 million iPhone 3Gs in the three days following the device's July 11 launch.

"Our 25 hours of counting iPhone sales in Apple retail stores throughout the country lead us to believe Apple is on pace to beat our previous estimate of 4.1 million iPhones for the September quarter," Munster said.

In total Munster expects the company to sell 1.78 million units at its US retail stores and a further 900,000 phones through its collaboration with US cellphone provider AT&T. US sales will constitute 53 per cent of the global total, Munster forecast.