By Kasper Jade

Published: 03:00 PM EST

Apple on Tuesday is likely to announce its best-ever June quarter for Mac sales, as new market data implies the company sold approximately 2.6 million systems during its third fiscal quarter.

Macs

In a note to clients Monday afternoon, Piper Jaffray analyst Gene Munster cited data from NPD which indicates that domestic Mac sales, which account for roughly 40 percent of the Mac maker's shipments, rose 16 percent in June following the introduction of more affordable MacBook Pros.

That's much better than the flat to 5 percent increase Munster had been anticipating and, when analyzed alongside previously released NPD data for the months of April and May, lead the analyst to predict that Mac sales for the three-month period ended June could run as high as 2.6 million.

If accurate, that total would not only trump Wall Street's consensus estimates of 2.45 million Mac sales for the quarter, but also signal the best-ever June (fiscal third) quarter for Mac sales in Apple's history. Additionally, it would imply year-over-year Mac growth of 5 percent.

The most Macs ever sold by the Cupertino-based company during a June quarter came last year, when it reported moving 2.496 million units. Apple's all-time quarterly record for Mac sales was recorded during the September 2008 quarter, when it sold 2.611 million systems.

iPods

Meanwhile, NPD data for all three months of the June quarter suggests unit sales will decline about 13 percent year-over-year to 9.6 million units, which is fairly in-line with Munster's estimate of a 10 percent decline and the Street's thinking towards a 14 percent decline.

Guidance

Apple will provide actual sales figures for Macs, iPods and iPhones following the close of the stock market on Tuesday as part of it fiscal third quarter report. The same report will include the company's forecast -- or "guidance" -- for the current quarter that runs July through September.

Munster pointed out in his note to clients Monday that Apple over the past 12 quarters has guided per-share earnings and revenues 12 percent and 4 percent, respectively, below Wall Street's expectations. However, the analyst predicted the typically conservative company may for once guide in-line with estimates due to three primary factors.

The first, he said, is strong demand for new MacBook Pros introduced last month that has seen some models remain backordered by over a week on the Apple online store. Second, he sees the improved value proposition of the 13-inch MacBook Pro adding to the historically positive impact of the company's back-to-school promotion. And finally, he points to the aforementioned NPD figures, which are ahead of his plans.



"If the company follows its standard operating procedure of extremely conservative guidance relative to Street expectations, we believe it would be particularly over-conservative given the factors outlined above," Munster told clients. "While it is impossible to predict the company's language around guidance and the numbers, we believe it is more likely than usual that the company could guide September revenue in line with consensus."

The Piper Jaffray analyst, who is also forecasting June quarter iPhone sales of 5 million, maintained his Overweight rating and $180 price target on shares of Apple.