Tablet Sales Show Fresh Signs of Slowing: Gartner

A Gartner report predicted 2014 worldwide tablet sales of 229 million, up 11 percent from last year, when the market grew 55 percent.

"Some tablet users are not replacing a tablet with a tablet, they are favoring hybrid or two-in-one (PC) devices," said Gartner's Ranjit Atwal.

Gartner sees a pickup in tablet sales in 2015 to 272 million units, which would be growth of 18 percent. But the research firm said many tablet users are keeping the devices longer, limiting the market for replacements.

One of the fastest growing segments is "ultramobile premium" PCs, which include devices that can function as both PCs and tablets. Gartner sees the segment nearly doubling in 2014 to 37,000 units, and growing to 64,000 in 2015.

The survey comes ahead of new tablet launches from Apple expected to refresh its iPad lineup, and Google, which was to unveil an upgraded Nexus tablet using the Android operating system.

Gartner said Android is the largest operating system worldwide when counting PCs, smartphones and tablets, with 313 million unit sales expected in 2014. Apple's iOS and Mac operating systems were second with 167 million unit sales expected, and Microsoft Windows third with 141 million.