By Katie Marsal

Published: 01:00 PM EST

After analyzing October sales data from market research firm NPD, investment bank Piper Jaffray said Wednesday it expects Apple will sell a record 25 million iPods during the three-month period ending December.

"While it is way too early to make a definitive call on December quarter iPod results, we have analyzed the first month of NPD data for the quarter and found that it suggests iPod units of 24 million to 25 million," analyst Gene Munster wrote in a brief research note.

"The 24 million to 25 million unit approximation is based on various assumptions and is an extrapolation of one month of data," he added, "when the second month of data is released, our analysis will likely lead to a slightly different iPod unit figure than what our analysis suggests based on the first month of data, so we believe investors should supplement this data point with other information."

Prior to Wednesday's NPD results, the analyst had been modeling the Cupertino-based company to sell approximately 23.5 million of the digital media players during the December quarter, slightly above Wall Street consensus estimates of 23 million. Therefore, he said, the October data is promising.

Munster's analysis of NPD iPod unit data starts by looking at the percentage contribution in NPD data from each month of the quarter in past December quarters. He noted that over the past three December quarters, iPod unit shipments were broken down monthly, on average, as follows: 12 percent (October), 24 percent (November) and 64 percent (December).

However, in quantifying this years percentage breakdown, the analyst conservatively factored in a larger-than-average October monthly contribution of 15 percent given the fact that the new iPods announced in September are radically different from the previous models.

"Apple has announced new iPods in September for the last 3 years, but this year's models are significantly more innovative than the past upgrades," he explained. "As such, we believe the new iPods are driving sales in Oct. to a greater degree than they have in the past."

In using the first month of NPD data and the typical percentage of iPods shipped in the first month, Munster then extrapolates those figures to reach his estimate for what NPD data will look like for the full December quarter.

Apple's current single quarter iPod sales record was achieved last year, when it sold just over 21 million iPods during the three-month period ending December, 2006.