By Katie Marsal

Published: 11:45 AM EST

With supply of the iPhone 3GS finally catching up with strong demand from consumers, a new analysis predicts that Apple will sell 7 million phones during the September quarter.

If true, the numbers from Gene Munster, senior research analyst with Piper Jaffray, would be an improvement from the 5.2 million handsets sold last quarter, and the 6.8 million iPhones shipped in the fourth quarter of 2008. When the iPhone 3GS first launched, supply constraints led to store managers recommending the $99 iPhone 3G over the higher end models. But a recent check of various stores found that the trend is no longer in effect.

"Our checks indicate store managers are increasingly recommending the 3GS, and we believe this is driven by improved availability of the 3GS at most AT&T stores," Munster wrote. "Overall, the iPhone remains the best selling device and our August checks indicate the iPhone took share from BlackBerry, the Nokia E71x, and most other competitor products."

The report states that all models of the iPhone, including the iPhone 3G, are reporting strong sales. But increased sales of the iPhone 3GS in particular are seen as a "positive indication" for iPhone sales during the third quarter.

Munster has reiterated his prediction that Apple will ship 7 million handsets in the September quarter. He has maintained an overweight rating for AAPL stock and has a $186 price target.

The senior research analyst expects to see the stock's price dip Wednesday after the scheduled iPod event. He said based on historical averages, the price will drop about 1 percent following the announcements. Munster does not believe that Apple will reveal any unexpected products Wednesday, but will introduce a new iPod touch, iPod nano and iPod classic. He also expects Apple co-founder Steve Jobs to be present to make the announcements.