Competition to Apple’s highly successful iPad hotted up as Samsung and Toshiba unveiled rival tablet PCs that they hope will steal some of the Californian giant’s thunder.

Samsung’s Galaxy Tab, presented at the IFA electronics trade fair in Berlin, Germany, has a seven-inch (17.8-centimetre) touchscreen, slightly smaller than the iPad’s 9.7 inches, and uses Google’s Android 2.2 operating system.

“Samsung recognises the tremendous growth potential in this newly created market and we believe that the Samsung Galaxy Tab brings a unique and open proposition to the market,” said mobile communications unit head JK Shin.

The Galaxy Tab, weighing 380 grammes - almost half the iPad’s weight -launches in Europe in mid-September, and in other markets including the United States, South Korea and elsewhere in Asia in the coming months.

But the South Korean firm gave no indication, however, of whether the Galaxy Tab will undercut the iPad on price, which retails from US$499 in the United States - or €499 in Europe - for the basic model.

Reports in the trade press said that the Galaxy Tab will be more expensive, at €799 in Germany and €699 in France.

Toshiba meanwhile lifted the lid in Berlin on its Folio 100, which boasts a slightly bigger screen than the iPad - 10.1 inches - and which will reportedly sell for a competitive €399.

The Japanese firm aims to have the Folio 100 hit the shops in Europe in the fourth quarter. And in another blow to Microsoft, the gadget runs off Android.

Apple sold more than three million iPads in the 80 days after they went on sale in the United States in April, with demand so strong that some US customers had to wait several weeks to get their hands on one.

Since then, the device, which uses Apple’s own MAC iOS operating system, has gone on sale in more than a dozen other countries and is poised to hit the shelves in China, the world’s largest internet market, later this month. The success caught California-based Apple’s competitors on the hop and they have been rushing to respond with their own tablet PCs, or “iPad killers” as they are collectively known.

Samsung’s South Korean rival, LG Electronics, has promised to release a tablet PC using Android before December. Microsoft is also said to be about to unveil the Courier while Hewlett-Packard is pinning its hopes on its Slate.