Reports have been swirling for months about the smaller version of the market-leading iPad, but Apple has made no comment.

The report, citing "people familiar with Apple's plans," said the invitation-only event will be on a Tuesday, breaking with the company's tradition for Wednesday announcements.

If confirmed, it will come three days prior to the release of Microsoft's new Surface tablet and two days before Apple reports quarterly earnings.

The Wall Street Journal, also part of Dow Jones, has reported that Apple has begun production of 10 million of the new iPads.

Various reports have cited the specifications of the new tablet and some pictures have also leaked. It is expected to have a screen of 7.85 inches (20 centimeters) compared with 9.7 inches for the current iPad.

The 10-inch iPad has long dominated the tablet market, but faces a growing challenge from smaller models like Amazon's Kindle Fire, the Google Nexus 7 and the Samsung Galaxy.

Apple shares were up 0.5 percent at $628.58 in midday trade.

The Galaxy S III Mini has a four inch high-definition touch screen, compared to the 4.8 inch version on it's larger Samsung sibling, but the size reduction is offered at a technical price.

The display has a lower resolution of 800x480 pixels compared to 1,280x720 pixels, the camera is five rather than eight megapixels and the S III's dual-core 1.5GHz processor has been downgraded to 1GHz.

"It can be an optimal choice for consumers who are looking for more practical smartphones," Samsung said in statement.

The company gave no details on pricing or an eventual sales date.

The Mini's screen is the same size as the iPhone 5 launched last month by Apple, but its reduced feature set makes it more of a corner man in the heavyweight clash between the iPhone 5 and the S III.

Samsung and Apple are currently embroiled in a bitter legal battle spread over 10 countries over alleged patent infringements.

Initial reactions to the new Samsung product were underwhelming.

"The only iPhone it may be capable of beating is the 3GS from 2009," said a review in the Los Angeles Times, which said the Mini's inability to connect with 4G networks was "unacceptable for any phone trying to be a major player".

Wired magazine bemoaned the lower resolution on the touch screen and said the final product was a "big compromise in a small package".

But some industry analysts said comparisons with the features boasted by top-end smartphones were missing the point.

"This is a lower-end product and it is not really a competitor for iPhone 5," said James Song, a tech analyst at Daewoo Securities.

The Mini does boast many of the same software features as the S III.

It is powered by the latest Android 4.1 Jelly Bean operating system, packed with S Voice, a language recognition software, and Smart Stay which keeps the screen lit as long as you are looking at it.

Other features include direct call, which enables you to automatically dial a call simply by lifting the phone to your ear when reading a text message from your friend.

S Beam allows the user to share music files between Galaxy S III series and Galaxy Note II devices simply by tapping the phones together.

Shin Jong-Kyun, who leads Samsung's IT and Mobile Communications Division, told reporters earlier this week that the Mini was aimed at meeting strong demand in Europe for smartphones with four inch screens.

"Some people call the new model a lower-end version of the Galaxy S III but we prefer the mini tag," Shin said.