Apple's growth story in China now extends beyond the iPhone and iPad, with Mac sales there also continuing to outpace the U.S. in terms of year over year growth, according to a new report.

Analyst Ben A. Reitzes with Barclays Capital said in a note to investors on Wednesday that he's not concerned by recent domestic sales data that some have interpreted as slower-than-expected Mac sales growth in the U.S. The NPD Group released figures on Tuesday that showed U.S. Mac sales up 12 percent year over year, a number that still easily outpaced the rest of the industry.

But Reitzes still believes Apple's total global sales will be up 22 percent year over year, thanks largely to rapid expansion in China. He said his checks with industry sources indicated that Mac sales grew faster in China last quarter than they did in the U.S.

"We believe Mac sales remain relatively strong even as the economy weakens, benefitting from new stores in China and strong sales of the MacBook Air," he said. "Even though the economy and HDD shortages are concerns that could limit upside, we remain comfortable with our estimate for 22% (year over year) Mac unit growth for (the fourth quarter of calendar 2011) given overseas momentum — especially in China where growth is much higher."

Apple previously highlighted tremendous growth in its Mac platform in the Asia-Pacific region last April, when officials noted that Mac sales were up 76 percent in the region, compared to 25 percent in North America. But those figures represented an entire region, while Reitzes believes Apple's greatest growth will come from one nation: China.

In fact, he said he believes Mac growth for the quarter will prove to have been "really driven by China" when Apple publicly announces its earnings next week. The company's earnings release and subsequent conference call are scheduled to take place after markets close next Tuesday.

A poll released last November found that Apple was the most desirable PC brand in all of China. A survey of 1,553 Chinese consumers revealed that 21 percent of respondents were considering a Mac for their next PC purchase.

Beyond China, Mac sales for the holiday quarter will also be bolstered, Reitzes said, by the fact that there was an extra week of sales in just-concluded 14-week December quarter. He believes those extra seven days could help Apple by "several hundred basis points."

The benchmark for Apple was set in the company's September quarter of last year, when it sold a record 4.89 million Macs in the three-month span. If the company manages to top that sum, it could achieve its first-ever quarter 5-million quarter for the Mac platform.