NEW YORK: Sales of tablets like Apple's iPad are expected to almost double in the US over the next five years, fuelling increased competition between major technology brands.

Forrester, the research group, has predicted that American purchase levels of these gadgets will reach 24.1m units in 2011, compared with 10.3m in 2010.

A further 35.1m such items are anticipated to be snapped up in 2012, the organisation estimates.

Several manufacturers - including Motorola and Dell - offered previews of new products at this week's Consumer Electronics Show in Las Vegas, while Samsung's Galaxy Tab has also previously made a mark.

However, Forrester believes the "lion's share" of demand may well fall on Apple's pioneering slate for the immediate future.

"Despite many would-be competitors that will be released at CES, we see Apple commanding the vast majority of the tablet market through 2012," said analyst Sarah Rotman Epps.

"When Apple's iPad first debuted, we saw the device as a game-changer but were too conservative with our forecast."

Looking forward, Forrester suggested shoppers could acquire 39.8m appliances in 2013, although growth then slows slightly, delivering totals of 42.3m in 2014 and 44m in 2015.

More broadly, the simple sales figures do not tell the whole story, as a consistent turnover is probable.

"One major assumption that changed in our model is the replacement rate, which we think will be closer to that of MP3 players or iPhones than to that of PCs," Rotman Epps added.

"Tablets are proving themselves to be 'lifestyle devices' at home and at work, and as such we think consumers will upgrade to newer models more rapidly than they would a more utilitarian device like a PC."

Indeed, the number of these gadgets in circulation is pegged to rise from 26m in 2011 and 50.7m in 2012 to 67.7m in 2013 and 76.1 m in 2014.

Overall, 82.1m tablets should be active by 2015, equivalent to a third of the US online audience utilising such tools.

In the short term, the roll out of the iPad 2, due to hit store shelves later in 2011, is set to encourage this trend.

"Many first-gen iPads will end up entertaining the kids in the back of the car while Mom and Dad get the shiny new (likely Facetime-compatible) model," said Rotman Epps.

During CES, Lenovo, the Chinese tech giant, unveiled a hybrid wireless appliance, the IdeaPad, which serves as both a laptop and tablet, and is driven by Google's Android operating system.

"It is one device to balance life and work," said Leo Li, Lenovo's product manager.

"A keyboard is more important and Windows software more powerful for a lot of things you need to work, especially productivity and creating content.

"At the same time, people want to enjoy music, see videos, go to websites, read e-books, and play games in their personal lives."

Similarly, the EEE Pad Slider, developed by Asus, combines a keyboard and touchscreen, with Jonney Shih, the Taiwanese firm's chairman, hoping this instrument can find its own particular niche.

"We admire companies like Apple that offer great innovation, but they provide very limited choices for the customers," he said.

"Different kinds of customers have different kinds of needs, and the best way to better serve them is to provide choice."

Data sourced from Forrester, AFP, BBC; additional content by Warc staff