The iPhone 6 Plus alone accounted for 41 percent of all phablet sales in the US in the fall, according to research firm Kantar Worldpanel ComTech.
The iPhone 6 and 6 Plus have delivered a huge surge in sales for Apple globally, according to a new report.
For the three months ending in October, Apple's share of smartphone sales in Europe rose by 5.7 percentage points from a year ago to 20.7 percent courtesy of the new iPhones, market researcher Kantar Worldpanel ComTech said Wednesday.
That figure is significant considering that the phones didn't debut until September 19, specifically in the US, Australia, Canada, France, Germany, Hong Kong, Japan, Puerto Rico, Singapore and the UK.
"In major European economies, the US and Australia, Apple's share of sales has risen," Kantar strategic insight director Dominic Sunnebo said in a statement. "This success is particularly evident in Great Britain where Apple now has its highest ever share of sales with 39.5 percent" -- a spike of more than 10 percentage points from a year earlier.
"Most of these sales were driven by loyal Apple users," Sunnebo said. "Some 86 percent of British buyers upgraded from an older iPhone model, only 5 percent switched across from Samsung."
In the UK, the iPhone 6 outsold the 6 Plus by a four-to-one ratio, Kantar said.
The top reasons cited by UK consumers for buying the iPhone 6 were its 4G capability (51 percent), screen size (49 percent) and design (45 percent).
Apple's iOS mobile operating system still trails Google's Android in smartphone sales across the world. But the iPhone 6 took care of one competitive gap, namely screen size. From a 4-inch screen for the iPhone 5S and 5C, the iPhone 6 grew to 4.7-inch display, while the iPhone 6 Plus bumped the screen size to 5.5 inches.
In the US, iPhone sales gains weren't nearly as impressive, rising by just 0.7 of a percentage point to 41.5 percent market share compared with the same period a year ago. Verizon subscribers accounted for 42.2 percent of iPhone 6 sales, while AT&T customers made up 41.4 percent of sales, Kantar said. But AT&T subscribers gravitated toward the bigger-screened variant, accounting for 63 percent of iPhone 6 Plus sales.
The iPhone 6 outsold the 6 Plus by a ratio of three-to-one in the US, Kantar said. Still the iPhone 6 Plus itself captured 41 percent of hybrid phone-tablet -- or phablet -- sales in the US for the three months ended October. Sales of phablets, which Kantar defines as smartphones with screen sizes of 5.5 inches or more, accounted for 10 percent of overall smartphone sales for the period.
Buyers who opted for the iPhone 6 Plus said that screen size was the major motivation for the purchase, while 4G LTE compatibility was the second biggest factor. Among both iPhone 6 and 6 Plus buyers, 85 percent of those surveyed by Kantar were repeat iOS customers, while 9 percent jumped ship from Android.
Notably, Apple's iPhones accounted for four of the five top-selling smartphones in the US in the three months ending in October, Kantar said.
Apple did not immediately respond to CNET's request for comment.