Apple Inc. surpassed $700 in late trading Monday after announcing record first-day orders for the iPhone 5, fueling optimism Apple will keep generating the revenue growth that transformed it from a niche computer maker into the world's most valuable business.

Shares climbed as high as $700.44 after reaching a record $699.78 at the close in New York. The stock has advanced 73 percent this year.

The iPhone 5, which features a bigger screen, faster chip and a lighter body, sold 2 million units in first-day orders, more than double a record set by the previous model, Apple said. Since its 2007 debut, the device has become Apple's top-selling product, accounting for about two-thirds of the company's profit. Signs of robust demand reinforced expectations Apple will withstand competition from Samsung Electronics and Google in the $219.1 billion smartphone market.

Apple's surge gathered steam Friday after it began taking orders for iPhone 5. Apple's website said new orders wouldn't ship until Sept. 28, a week after the handset is due in stores, an indication that supply may be running thin.

"The initial batch is sold out," Shaw Wu, an analyst at Sterne Agee & Leach Inc., said in an interview. He raised his sales estimate for the quarter ending in September to 26 million units, from 23 million. "That could turn out to be conservative."

Apple surpassed Exxon Mobil to become the biggest company in the world by market capitalization last year after overtaking Microsoft Corp. as the most valuable technology company in 2010. Before his death in October, co-founder Steve Jobs mastered a strategy of pushing Apple beyond its core business of selling computers into new markets, including digital music and mobile phones. Each new family of products helped the company boost revenue while inducing investors to buy more shares.

Revenue increased to $35 billion in the June quarter from $1.73 billion in the last quarter before Jobs returned to Apple in 1997. Apple's shares crossed the $600 threshold in July, after passing $500 in February and $400 last year.

Sales of iPhones last quarter alone reached $16.2 billion.

As many as 58 million units of the iPhone 5 may sell by the end of the year, according to the average estimate of analysts surveyed by Bloomberg. That could generate as much as $36.2 billion in sales for Apple.

Apple has grown adept at keeping existing customers and drawing new ones through incremental improvements to the hardware and software of its products while also cultivating a developer community that cranks out thousands of applications for use on the company's phones and computers, said Dan Morris, chief investment officer at Morris Capital Advisors, whose largest holding is Apple.