Apple Inc.’s stock flirted with $300 Tuesday as investors high on the iPad’s promise pushed shares to a record peak. Analysts see few reasons to believe shares will stop there.

As was the case with the iPhone, Apple’s iPad is setting the standards for this generation of tablet computers as competitors scramble to match the design and functions.

So far, no credible challengers have hit the market. Microsoft Corp. CEO Steve Ballmer has promised Windows-based tablets, but so far there are no solid details. Meanwhile, tablets based on Google Inc.’s Android system are starting to emerge, but they have smaller screens than the iPad’s.

In the first quarter it was available, Apple sold 3.3 million iPads. That’s about three times the number of iPhones sold in the first full quarter the smart phones were on sale in 2007.

Rajesh Ghai, an analyst for ThinkEquity LLC, said he believes Apple is now generating about $3 billion a quarter in iPad revenue — not bad for a product category that didn’t exist before April. Analysts’ estimates for iPad unit sales in 2011 are in flux, with those on the conservative end putting the number around 20 million while more bullish forecasters say it could be 50 million.

“Clearly the iPad proved to be a hit beyond Apple’s wildest dreams,” Ghai said in an interview.

A few other factors are bolstering investors’ enthusiasm for Apple, which reports its quarterly results on Monday. The Cupertino, Calif.-based company is planning a big push in China, with 25 retail stores expected to open there by the end of next year.

There’s also the new slate of iPods, which Apple unveiled in September, in time for the profitable gadgets to make their way onto holiday shopping lists.

And investors may be choosing to believe increasingly loud buzz that Verizon Wireless will get its own version of the iPhone in 2011. In the U.S., the iPhone is only available on AT&T Inc.’s network, which is straining in some cities under the heavy volume of data consumed by iPhone users. Adding carrier partners could lure U.S. smart phone buyers who have been reluctant to switch to already-taxed AT&T.

Apple’s shares have climbed sharply and fairly steadily since the end of the dot-com bust, from about $7 per share in early 2003 to nearly $169 in the summer of 2008. The stock dropped below $100 per share in late 2008 and early 2009 as investors worried about the health of CEO Steve Jobs, but it has been gaining since March 2009. Shares set all-time high records on a split-adjusted basis several times this year.

Compare that with another well-known technology player, IBM Corp., which experienced a much choppier climb before reaching an all-time record Monday of $139.66, breaking the previous high reached in 1999.

Apple and IBM may be breaking new ground at the same time, but they’re not signs of a broader tech industry surge, said Nehal Chokshi, an analyst for Technology Insights Research-Southridge Research Group. These events are company-specific.

“IBM didn’t explode in the bubble, and Apple has had truly phenomenal growth,” the analyst said.

To be sure, there are a few dark specks marring an otherwise bright investment outlook. For one thing, Apple insists on sitting on more than $24 billion in cash, more than could reasonably be used for acquisitions, said BGC Partners analyst Colin Gillis. Some of that money should be going back to shareholders, the analyst said.

A $300-per-share price tag may look expensive in absolute terms, but Gillis and other analysts say it’s a reasonable number for a company that’s growing as quickly as Apple. (Gillis has a $350 price target for the stock.) In the April-to-June period, the company’s net income jumped 78 percent from the previous year to $3.25 billion as revenue rose 61 percent to $15.7 billion.

The worry, of course, is Apple’s growth will eventually slow.

“You can only have high growth if you’re not the biggest player. If you’re the biggest player, it’s hard for you to grow significantly faster than the market,” said Nehal Chokshi, an analyst for Technology Insights Research-Southridge Research Group. “Apple is becoming one of the biggest players.”

And not just the biggest player among consumer electronics companies: In May, Apple surged ahead of Microsoft to take the No. 2 spot on Standard and Poor’s 500, the market index used by most professional money managers. Now, the company is on a path to overtake Exxon Mobil Corp. as the largest company by market capitalization.

Chokshi said he sees Android challenging the iPhone, even among AT&T customers. With that in mind, the analyst is feeling more conservative about the stock than his peers. His price target: $315.

“I’m starting to get a little bit concerned that the stock might be getting ahead of itself,” Chokshi said. “Android is gaining some mind share. Not a lot, but some.”