Paul Sakuma / AP Apple customers Loan Thach, left, and Jason Payne try out the new iPhone at an Apple store in Palo Alto on Tuesday. Apple sold 270,000 iPhones in the first two days.

SAN JOSE, Calif. (AP) — Apple Inc.'s fiscal third-quarter profit soared more than 73 percent, fueled by demand for its Macintosh computers, the strength of its iPod media players and the sales of 270,000 iPhones in the first two days on the market.

Apple shares jumped more than 6 percent in extended-session trading Wednesday even as the company issued a conservative outlook that fell short of Wall Street's expectations.

For the quarter that ended June 30, Apple's profit rose to $818 million, or 92 cents per share, up from $472 million, or 54 cents a share in the year-ago quarter.

Sales grew to $5.41 billion from $4.37 billion last year.

Analysts polled by Thomson Financial expected Apple to report earnings of 72 cents per share on sales of $5.28 billion while Apple itself had projected earnings of 66 cents per share on quarterly sales of $5.1 billion.

"We're thrilled to report the highest June quarter revenue and profit in Apple's history, along with the highest quarterly Mac sales ever," said Steve Jobs, Apple's CEO. "IPhone is off to a great start — we hope to sell our one-millionth iPhone by the end of its first full quarter of sales — and our new product pipeline is very strong."

But for the quarter ending in September, Apple said it expects to earn about 65 cents per share on revenue of about $5.7 billion. Analysts were expecting earnings of 83 cents per share on sales of $6 billion.

The gadget maker's highly anticipated iPhone launched on June 29 and sold out within days. Wall Street analysts and investors have had lofty expectations for the multimedia cell phone, driving up Apple's stock more than 30 percent during the quarter.

Apple's silence on how many iPhones were available at launch added to the frenzy and analysts were hoping to gain some insight on the iPhone's initial sales impact and outlook when the Cupertino-based company was to discuss its quarterly earnings during a conference call late Wednesday.

Shares of Apple tumbled more than 6 percent Tuesday after AT&T Inc. — the iPhone's exclusive U.S. carrier — said it activated 146,000 iPhones on June 29 and 30, a number that disappointed investors following some analyst forecasts that Apple would sell 500,000 or more iPhones in its first weekend.

On Wednesday, before Apple's results were announced, its shares rose $2.37, or 1.8 percent, to close at $137.26. In heavy-volume trading after hours, shares as fell as much as 6 percent before they rose by more than 6 percent to $145.50.

The reason for the discrepancy between Apple's and AT&T's numbers was unclear. But service activation problems may be the reason.