wifi devices researchTablet shipments totaled 27.8 million worldwide in 3Q 2012, 49.5% higher than the year-ago period and 6.7% higher than that for 2Q 2012, according to preliminary data from the IDC Quarterly Tablet Tracker. Android tablet shipments surged, with Amazon and Samsung sales leading the way, while Apple’s market share “slipped notably.”

“After a very strong second quarter, Apple saw growth slow as both consumer and commercial (including education) shipments declined, and rumors of a forthcoming iPad mini began to heat up,” commented Tom Mainelli, research director, Tablets at IDC.

Apple’s global tablet market share fell from 65.5% in 2Q to 50.4% in 3Q while IDC’s other Top 5 tablet vendors all gained market share. Driven by shipments of its Galaxy Tab and Note 10.1, Samsung posted the most impressive gain in 3Q, shipping 5.1 million tablets, up 115% from 2Q 2012 and a whopping 325% increase over the previous year, when it shipped 1.2 million tablets.

“We believe a sizable percentage of consumers interested in buying an Apple tablet sat out the third quarter in anticipation of an announcement about the new iPad mini,” Mainelli added. “Now that the new mini, and a fourth-generation full-sized iPad, are both shipping we expect Apple to have a very good quarter. However, we believe the mini’s relatively high $329 starting price leaves plenty of room for Android vendors to build upon the success they achieved in the third quarter.”

“Samsung took advantage of an opportunity in the second quarter,” commented Ryan Reith, program manager, IDC’s Mobile Device Tracker. “The company offers a wide range of tablet offerings across multiple screen sizes and colors, and that clearly resonated with more buyers this quarter. Its growth to 18.4% of worldwide market share during the quarter represents the first time a competitor has attained this level of share since the original launch of the iPad.”

Following Apple and Samsung in IDC’s Top 5 were Amazon, ASUS and Lenovo. All three registered sequential growth quarter-over-quarter, while ASUS and Lenovo posted year-over-year gains as well. Strong shipments of its Google-branded Nexus 7 tablet fueled ASUS’s market share gain, while strong China sales fueled Lenovo’s.

Amazon didn’t have a tablet offering on the market in 3Q 2011, but it announced new 7-inch and 8.9-inch Kindle Fire HD tablets late in 3Q, IDC noted. Amazon also began shipping its new 7-inch HD Kindle in 3Q as well as a “refreshed version” of its original 7-inch Fire in mid-September. All this resulted in Amazon’s global tablet market share jumping from 4.8% in 2Q to 9% in 3Q, despite only shipping in the US, according to IDC’s latest Quarterly Tablet Tracker data.

“Competitors are turning up the pressure on market leader Apple,” Reith continued. “With the recent introduction of a number of Windows 8 and Windows RT tablets, consumers now have a third viable tablet platform from which to choose. However, price points are critical in tablets, and Microsoft and its partners will have a tough time winning a share of consumer wallet with price points starting at $500.”