Apple Inc. delayed by a month the international debut of its iPad tablet computer after shipping more than 500,000 of the devices in a week and underestimating how quickly they would sell in the U.S.

Less than a week after Chief Executive Officer Steve Jobs said the company was building iPads “as fast as we can,” Apple said in a statement that demand is “far higher” than it predicted. Apple lacks supply for several weeks and made a “difficult decision” to delay global sales until end of May.

Early sales signal Jobs is off to a good start winning buyers for a new category of mobile device between smartphones and laptop computers. The supply problems suggest the iPad is “resonating” with users beyond the fans who line up first to buy any new gadget from Apple, said Gene Munster, an analyst with Piper Jaffray & Co. Misjudging demand may also inhibit near-term sales, he said.

“It’s an embarrassment for Apple to push back the international demand by a month -- the delay is a sign that was not intended,” Munster said. He rates Apple shares “buy” and doesn’t own any. “It’s good news because the sustainability of the demand is better than we thought, with the demand coming from people who are not necessarily Apple fanatics. But it’s bad news because they can’t produce enough right now.”

Apple may not be getting enough of the parts it needs for the iPad, said Yair Reiner, an analyst at Oppenheimer & Co. The iPad is a touch-screen tablet with a 9.7-inch (25-centimeter) LED-backlit display with technology that Apple says delivers an “ultra-wide” viewing angle and consistent color. The iPad also includes a new chip designed by Apple.

‘Some Glitches’

“Scaling manufacturing of the iPad has been quite a challenge -- there are a number of key components that go into that device that have never before had to scale to mass market production,” Reiner said. “We shouldn’t be so surprised that some of those start to hit some glitches.”

Even so, the delay may not hurt Apple’s sales prospects for the iPad outside the U.S. because there is a dearth of competing products, said Reiner and Charlie Wolf, an analyst at Needham & Co. in New York.

“You should never underestimate how Steve Jobs sees where the computing market is going,” said Wolf, who recommends buying the stock and owns it himself. “It may be a modest disappointment for Europe and the other countries, but it’s in no way going to damage iPad sales.”

Apple, based in Cupertino, California, rose $3.26, or 1.3 percent, to a record $245.69 at 4 p.m. New York time in Nasdaq Stock Market trading. It has more than doubled in the past year.

‘Try Harder’

The iPad went on sale April 3 in the U.S. and drew crowds to stores across the country, rivaling the frenzy seen when the iPhone was introduced in June 2007. Apple said it sold more than 300,000 iPads on the first day.

Apple had planned to start selling the device in Australia, Canada, France, Germany, Italy, Japan, Spain, Switzerland and the U.K. this month.

Jobs, speaking at a company event April 8, said he had “butterflies” in his stomach before the iPad debut as he wondered whether customers would embrace the new device. The lines at Apple’s U.S. retail stores and Best Buy Co. outlets show “people get it,” leaving Apple scrambling to meet demand, he said.

“We’re making them as fast as we can,” Jobs, 55, said last week. “Our ramp is going well, but evidently we can’t quite make enough of them yet so we’re going to have to try harder.”

The iPad is sold out at some stores, UBS AG analyst Maynard Um said in a note today. He said his estimate of 1.2 million iPads shipped this quarter is probably conservative.

1.8 Million

Wolf had forecast sales of as many as 300,000 iPads for the first weekend and 1.25 million for the quarter ending in June. Munster expects June quarter sales of 1.3 million iPads and said shipments of 1.8 million units may be “doable” if Apple fixes its supply issues.

Apple has suffered from shortages before. Its iPhone 3G was sold out at almost all of its U.S. retail outlets 10 days after it was introduced in July 2008. A year later, soaring sales of the iPhone 3GS left it with too few units to meet demand.

Apple is betting the iPad, which starts at $499, is enticing enough that consumers are willing to pay a premium over low-cost notebooks. Rivals such as Microsoft Corp. have failed to turn tablet computers into popular consumer devices.

The international delay means consumers outside the U.S. may need to keep paying extra to buy the iPad from friends and entrepreneurs who brought them from the U.S. IPads have fetched 100,000 rupees ($2,250) in India and one purchaser in the U.K. paid $5,500, more than 10 times the U.S. asking price, according to online auctioneer EBay Inc.

Lack of Competitors

“There’s nothing on the market like it, and there won’t be for months,” Wolf said. “People are not going to go out and buy a competing product because there’s no competing product.”

Users can surf the Internet, peruse digital books, watch video and play games on the touch-screen iPad. Tablets have been available in one form or another since the 1990s, without ever catching on. They account for less than 1 percent of the personal-computer market, according to researcher Gartner Inc.

Hewlett-Packard Co., the world’s largest maker of personal computers, has said it plans to start selling a touch-screen slate device this year. Dell Inc. also showed a tablet design at the Consumer Electronics Show in Las Vegas in January.

Apple is selling three of the six iPad versions it plans to offer, with first buyers getting models that connect to the Web via Wi-Fi. IPads that run on so-called third-generation mobile- phone networks will go on sale later this month in the U.S. Apple said today it has taken a “large number” of preorders for the 3G models.

Apple said it will announce international pricing and begin taking online preorders on May 10. Vodafone Group Plc said it will offer price plans for the iPad in Australia, Italy, Spain, Germany and the U.K., starting at the end of May. Rogers Communications Inc. said it will offer service for the device in Canada.