Apple shares briefly topped $600 in early trading on Wall Street on Thursday, a day ahead of the launch of the next-generation iPad.

Apple Inc.'s stock touched $600 for the first time, the day before the company's latest iPad goes on sale.

The stock reached $600.01 just after the market opened and was up $3.76 at $593.34 after the half-hour of trading.

Apple is the world's most valuable company, with a of nearly $555 billion. It topped $500 billion for the first time in late February, a market value peak where few companies have ventured.

Anticipation is high for Apple's latest creation. Some industry experts believe the Cupertino, Calif., company could sell 1 million of the new on Friday, when it becomes available to the public. Apple has already stopped taking advance orders for Friday and said customers should expect a two- to three-week wait for purchases made through its online store.

There were 15.4 million iPads shipped in Apple's most recent quarter, which included the critical . That amount was more than double its iPad sales the year before.

The updated iPad will not have a new name. Upgrades include a sharper screen, driven by a faster processing chip that acts as the "brains" of the device. The new features will make the slightly thicker and heavier than the iPad 2, because it needs a larger battery to power the high-resolution screen.

Prices aren't changing from the previous models. They will start at $499. Versions capable of accessing will cost $629 to $829.

The new iPad will go on sale Friday in the U.S., Canada and 10 other countries. It will go on sale in 25 more countries next week.