A customer walks out after shopping at an Apple store in downtown Shanghai.—Reuters

The invitation-only event will be held at 1 p.m. EST (1800 GMT) on March 7 at the Yerba Buena Center for the Arts in San Francisco, where the company also introduced the last two generations of iPads.

Apple, which sent the invitation to reporters by email on Tuesday, did not divulge details of the event beyond saying: “We have something you really have to see. And touch.”

The invitation featured a partial picture of the touchscreen of a device resembling an iPad.

Apple launches are some of the hottest events on the tech calendar, scrutinised by fans, investors, the media and industry insiders alike.

The third iteration of a device that has helped put pressure on demand for traditional laptops and computers is expected to boast a faster, quad-core processor and a higher-definition screen.

Some analysts and industry experts expect 4G wireless capability, ensuring that the iPad remains current as cutting-edge broadband technology from Verizon Wireless and other carriers gains momentum.

Verizon Wireless is a venture of Verizon Communications Inc and Vodafone Group Plc.

“The picture is zoomed in on an icon and I don't see any pixels in that icon,” Avi Greengart, analyst at Current Analysis, said, underscoring how industry experts pick apart even Apple's communiques for hints of what to expect.

“You don't need exceptional foresight to guess that Apple is likely looking at a higher resolution display.”

TAKING ON PCS  The company's market value has climbed steadily in past weeks, buoyed by anticipation over its latest gadget as well as by hopes that Apple will finally accede to shareholders' demands it return some of its $98 billion war chest of cash and securities.

On Tuesday, Apple shares closed at a record high of $535.41 in heavy trading on the Nasdaq, up 1.8 per cent on the day.

Apple iPad tablet sales doubled in the December quarter to 15.43 million units. The company has sold about 55 million iPads since it introduced the device in 2010.

It may be looking to “make further inroads into the general computing market” with the newest iPad, Greengart said.

Chief Executive Tim Cook has often said that he expects tablets to outsell personal computers eventually. Cook, who took the company's helm after visionary Steve Jobs died in October, will likely lead the event, with ample help from marketing chief Phil Schiller and other executives.

With the iPad 2 starting at $499, investors will also be watching to see if Apple plans to discount it, creeping farther down the price chain and closer to the Fire, to broaden the iPad's appeal.