Nearly half the smartphones activated over Christmas were iPhones

Apple came away the winner in mobile device holiday sales worldwide amid a shift to bigger screens, a survey showed.

The survey by the Yahoo-owned analytics firm Flurry showed Apple accounted for 49.1 percent of smartphones and tablets activated over the Christmas week, compared to 19.8 percent for South Korean rival Samsung.

"Christmas is traditionally the biggest day of the year for new smart-device activations and app downloads, and 2015 was no exception, with new device activations and app installs shattering record after record," Flurry vice president Jarah Euston said in a blog post Monday.

The survey found more consumers around the world opting for large-screen smartphones or "phablets," which are often used in place of a tablet computer.

Apple entered the phablet market last year with the iPhone 6 Plus and upgraded it this year with the 6s Plus.

"Of course the introduction of an Apple phablet -- and subsequently the iPhone 6s Plus -- had a lot to do with the strength of phablets," Euston said.

"But that's not the whole story. When we examined the form factor distribution by operating system we saw that for the first time phablets accounted for half of all Android devices! The popularity of the Samsung Galaxy Note and its imitators have changed the Android game, especially in Asian markets."

For Apple buyers, around 12 percent of purchases with phablets, according to Euston.

"This appears to be coming at the expense of medium phones and small tablets as more users opt for the size in between the iPhone and iPad Mini," she said.

Overall, 27 percent of the devices were phablet-sized, which generally means a display of 5.5 to seven inches (about 14 to 18 centimeters).

"In the early days it appeared that phablets were stealing share from tablets," Euston said. "For the first time in 2015 though, it appears consumers are opting for phablets -- not instead of a tablet -- but instead of a smaller-sized phone."

Although Apple held its dominant position, its market share was down 2.2 points from a year ago while Samsung added 2.1 percentage points, Flurry said.

Microsoft devices accounted for just two percent of the market, down from 5.8 percent in 2014, and Sony fell out of the top five.

South Korea's LG was fourth with a 1.7 percent share and China's Xiaomi accounted for 1.5 percent.

Christmas was the biggest day of the year for app downloads, with more than twice as many installations as on a typical December day, according to Flurry.

"For app developers who scrambled to ship apps before the holidays and spent heavily on app marketing, it appears that the efforts have paid off," Euston said.