SAN FRANCISCO - Mass production of a smaller and cheaper version of Apple's iPad tablet computer has started, US media reported on Wednesday.

LG Display and AU Optronics, two leading LCD panel manufacturers based in Asia, already began manufacturing the LCD screens for Apple's new device in September, The Wall Street Journal said in a report, citing executives at Apple's Asian suppliers.

Apple has kept the screen size of its iPad unchanged at 9.7 inches since the product debuted in January 2010.

In comparison, a smaller Apple tablet will feature a 7.85-inch liquid-crystal display with a lower resolution than the latest iPad, according to The Wall Street Journal.

The launch of a smaller iPad is seen as Apple's move to stay competitive against rivals such as Google and Amazon, which have introduced 7-inch tablets at prices no more than 200 U.S. dollars. The cheapest iPad starts from nearly 400 dollars.

The Fortune magazine on Monday reported that Apple is rumored to be sending out press invitation on October 10 to a special event, which might be held on October 17 to unveil the smaller iPad.

Apple has not yet commented on the reports.