By Katie Marsal

Published: 09:00 AM EST

Sales of Apple's Mac and iPod products bounced back last month following a disappointing November, helping the company's performance in those segments pull slightly ahead of Wall Street's consensus estimates for the December quarter.

Extrapolating data released by market research firm NPD on Monday, Piper Jaffray analyst Gene Munster said Mac sales appear to have risen 4 percent year-over-year during the month of December, a welcomed boost from November figures that saw sales growth dip briefly into negative figures.

With data for the past three months now in hand, Munster said he believes Apple sold anywhere from 2.45 million to 2.55 million Macs during the December quarter, which would represent yearly unit growth in the 6 to 10 percent range. He's banking on the midway point of 8 percent, which he notes is right in line with the expectations from investment bankers on Wall Street.

"We believe this data will be perceived as a slight positive given the rebound in the month of December to +4 percent year-over-year, up from -1 percent year-over-year in the month of November, which some investors were using as an assumption for December," the analyst wrote in a note to clients. "We expected growth rates for Mac to decline in the months of November and December; the December NPD data indicates Mac units in line with conservative Street expectations."

In terms of costs, the data from NPD indicates that Mac prices remained relatively flat quarter to quarter, which came as a surprise to Munster who had been modeling average selling prices (ASPs) of the system to shoot up some 12 percent following the introduction of premium-priced MacBooks, MacBook Pros, and MacBook Airs during the month of October.

Meanwhile, a similar analysis of iPod sales data leads the analyst to estimate Apple will announce December quarter iPod sales of approximately 19 million to 20 million unit, noticeably ahead of Wall Street's expectations of 18.6 million units.

"This range implies year-over-year iPod unit growth of -14 percent to -10 percent versus the Street at -16 percent year-over-year," he wrote. "Given concerns regarding iPod weakness, we believe the segment's outperformance relative to Street expectations is a positive."

NPD data suggests iPod ASPs continued on their year-long decline during the December quarter, falling some 12 percent. Munster, who did not specify an average sale price for the digital media players during the quarter, said he had been modeling for iPod ASPs to drop only one percent.

"The bottom line is that it is difficult to predict iPod ASPs from NPD, but we continue to believe a slight quarter-over-quarter down tick is likely," he wrote. "Our unit approximation is based on various assumptions, one of which is NPD data; others include international iPod demand and the availability of lower-priced iPods this year."

Munster maintained his Buy rating on shares of Cupertino-based Apple with a $235 price target. For the 2009 calendar year, he's expecting Mac sales to grow 10 percent while iPod sales decline some 20 percent.