Sony launched its first tablet computers in an ambitious attempt to grab the second spot in the market more than a year after Apple's iPad revolutionized mobile computing.

The gadgets will use an operating system based on Google's Android 3.0, said Kunimasa Suzuki, deputy president of the consumer products and services group.

These will be the first tablets to enable the use of PlayStation games, said Suzuki, who produced one of the glossy black devices from his jacket pocket during a media launch on Tuesday.

Suzuki raised eyebrows in January when he told reporters at the Consumer Electronics Show in Las Vegas that Sony was aiming for the No.2 spot in the tablet market within a year even though it had yet to put a product on the market.

That effectively means they have to beat Samsung, which is a very tough rival, said Nobuo Kurahashi, an analyst at Mizuho Investors Securities in Tokyo. Although this is an interesting product, they have already been left behind in televisions, so it's not going to be easy.

Sony's Kazuo Hirai, seen as a likely successor to CEO Howard Stringer, made his first public appearance on Tuesday after the company promoted the gaming division chief to the number 2 position last month.

Sales of tablet devices are expected to quadruple to about 294 million units between 2011 and 2015, with almost half that Android-based, research firm Gartner has forecast.

Sony's tablets, code-named S1 and S2, are WiFi and 3G/4G compatible. S1 has a 9.4-inch display and is designed make it easier to hold for long periods of time, Sony said. The S2 has two 5.5-inch displays in a clamshell design.

The company, which had been criticized for failing to come up with a tablet offering after iPad's launch in April 2010, has emphasized the need to differentiate its tablet from rivals, even if that takes time.

Although it's a late comer in the market, it has potential as what you need is just one big uniqueness that can sell to customers be it design or whatever, said Lee Sun-tae, an analyst at Meritz Securities in Seoul.

By the same token it can be just one of another Android gadgets flooding the market amid intensifying competition.

In a bid to tap burgeoning demand, competitors including Samsung Electronics -- whose Galaxy Tab is Apple's strongest competitor in the tablet market -- and Motorola, LG Electronics and HTC are flooding the market with tablets running Android.

Hewlett-Packard Co unveiled its entrant in the tablet race in February.

Shares in Sony, which unveils its quarterly results on May 26, fell 2.1 percent on Tuesday.

(Writing by Anshuman Daga; Additional reporting by Miyoung Kim in Seoul)