MacBook Air shipments jump as notebooks plummet overall

Apple’s (s appl) MacBook Air continues to be a hot seller according to the latest sales estimates coming out of Apple’s Asian supply chain. Shipments of the ultra-slim notebook were up to 1.2 million units in the fourth calendar quarter of 2011, up from 1 million the quarter before.

The MacBook Air was the only notebook that saw increased shipments during the quarter, according to Digitimes Research, which said on Monday that notebook shipments slowed by 8.7 percent sequentially to 48.59 million units worldwide during the quarter.

In Apple’s last quarterly earnings report, it reported 4.89 million Macs sold, meaning if we use Digitimes’ estimate of 1 million MacBook Airs sold, the notebook represented roughly 20 percent of the total. We know Apple’s iMac is also performing well, but it’s logical to assume the Air is growing in influence in terms of the overall Mac picture. Expect that trend to continue, since analysts expect the so-called Ultrabook category to explode in the next six years.

Apple doesn’t usually break out sales of individual Mac lines from the overall Mac category total, but it will still be interesting to see if it has any official comment on the success of the Air during its quarterly earnings conference call on Jan. 24.