Tech giant Microsoft today launched revamped Surface tablets at a price starting from USD 449 in a bid to take on bigger rival Apple's iPad.

"Surface 2 and Surface Pro 2 each benefit from significant updates, including improvements to processing power and battery life, to display and camera resolution," Microsoft said in a statement.

The two new Surface models will be available at Microsoft retail stores, and select third-party retailers in 22 initial markets, including Canada, France, Germany, Hong Kong, the US and the UK, from October 22.

The tablets would be available in China from early November while additional markets will be announced in the coming months, the statement said. However, customers can pre-order the two tablets from tomorrow.

Shares of Microsoft were marginally up at USD 32.83 on Nasdaq.

The 10.6-inch Surface 2 will ship with Windows RT 8.1, bringing improvements in key areas such as personalization, search, multitasking, built-in apps, the Windows Store experience and cloud connectivity, it said.

The tablet offers up to 10 hours for video playback, full-size USB port and a 3.5-megapixel front camera and 5-megapixel rear camera. It is available in 32GB and 64GB configurations with price starting from USD 429.

Surface Pro 2 is capable of running virtually all Windows software and is powered by a fourth-generation Intel Core i5 processor which delivers increased performance and up to 60 per cent longer battery life than predecessor Surface Pro, the statement said.

The software giant had launched its own Surface tablet last October but its sales dragged compared to Apple's iPad and Google's Nexus tablets. The company had to take charge of USD 900 million for unsold inventory and price drop in the last fiscal.

Recently, Microsoft launched a trade-in offer of Apple's iPads at select stores for a minimum of a USD 200 gift card. The 16GB Apple iPad mini comes at USD 329.

According to research firm IDC, Windows-based tablets had 4 per cent share in the second quarter of 2013. The shipments of Windows tablets grew to 1.8 million in Q2 2013, from arounf 300,000 in Q2 2012.

However, Andriod-based tablets ruled the market with 62.6 per cent share in the second quarter of 2013, followed by Apple's iOS with 32.5 per cent share.

Apple was the largest vendor that shipped 14.6 million units of tablets during the period. Microsoft was not in the top five tablet vendors, according to IDC.