Sales of tablet computers like Apple's iPad are expected to soar from nearly 20 million units this year to 55 million next year and over 208 million in 2014, market research firm Gartner said Friday.

Gartner said North America will account for 61 percent of tablet computer sales this year but its share will drop to 43 percent in 2014.

Gartner forecast worldwide sales of tablet computers of 19.5 million units in 2010, 54.8 million units in 2011 and more than 208 million units in 2014.

Apple began selling its iPad in April and a number of other companies have announced plans to begin producing the multi-media devices, which can be used to surf the Web, read electronic books, watch video and more.

Gartner said the explosion in tablet computers will impact sales of devices in other segments including netbook computers, the small laptops also known as mini-notebooks.

"The all-in-one nature of media tablets will result in the cannibalisation of other consumer electronics devices such as e-readers, gaming devices and media players," Gartner research vice president Carolina Milanesi said.

"Mini notebooks will suffer from the strongest cannibalisation threat as media tablet average selling prices drop below 300 dollars over the next two years," Milanesi said.