NEW YORK (CNN/Money) - Apple Computer warned Tuesday that its current-quarter sales and profit will fall short of analysts' forecasts as customers keep cutting spending on new computers.

The warning came as Apple (AAPL: Research, Estimates) reported June-quarter earnings per share that tumbled 47 percent from a year ago but matched targets.

Shares of Apple slumped more than 8 percent in after-hours trade. The latest decline comes as Apple launches a new advertising campaign and opens retail stores to lure customers. The company is also readying for Wednesday's Macworld Expo in New York, a big draw for Apple's band of loyal buyers.

Looking forward, Apple said sales in the fourth quarter ending in September will be flat with the June quarter's $1.43 billion. That's below the $1.5 billion in third-quarter sales that analysts surveyed by First Call were looking for.

As for earnings, Apple said it expects a "slight" current-quarter profit; analysts were calling for 14 cents a share.

Fred Anderson, Apple's chief financial officer, said during a conference call with investors that the lowered guidance reflects "what we believe will continue to be a tough economic environment."

The warning spooked investors. Apple shares tumbled $1.46 to $16.40 after hours, after losing 37 cents in the regular session. They are down 31 percent this year.

Cupertino, Calif.-based Apple posted a net profit of $32 million, or 9 cents per diluted share, for the third quarter. That's down from a net profit of $61 million, or 17 cents per diluted share, in the year-ago period. Sales in the quarter ended last month fell 3 percent to $1.43 billion.

The fourth-quarter warning comes a month after Apple cut third-quarter guidance.

In the conference call, Anderson detailed the trying period, saying half the weakness came from Europe and the remainder was split between the United States and Japan.

In the United States, declining tax revenues sapped municipal budgets, hurting sales from schools, which are big Apple customers. Consumers did not buy enough Macs during seasonal events like graduations and Father's Day, Anderson said.

But Apple executives were somewhat upbeat Tuesday. The company said it shipped 808,000 Macintosh units during the quarter, down just 2 percent from the year-ago quarter. Apple has $4.3 billion in cash.

"Even in this extended worldwide downturn, Apple is continuing to be profitable and continuing to innovate," Steve Jobs, Apple's CEO, said in a statement.

Like many computer makers, Apple's profits peaked in 2000. It's been tough ever since as consumers and businesses cut technology spending.

Still, Apple has returned to profitability after losing money in the December quarter of last year.

In April, Apple unveiled its first personal computer designed exclusively for schools, the eMac, a move some say is intended to defend its position in the education market.

Apple's customers may be less interested in earnings and more focused on Wednesday's Macworld Expo in New York. That's when the company often unveils new products.

After opening two retail stores during the latest quarter, bringing the total to 31, Apple will open its first New York retail store on Thursday.

To lure more new customers, Apple this month launched an advertising campaign featuring what it says are real people who have switched to Macs from PCs.

"Apple is committed to making the investment to gain market share and grow the company," Anderson said.

Market leader Dell Computer poses a major obstacle. Dell (DELL: Research, Estimates) has benefited from the uncertainty that surrounded the Hewlett-Packard/Compaq merger, which closed earlier this year, and from its ability to manage inventory by selling directly to customers.

Unlike Apple, Dell recently raised profit guidance.

As for the current quarter, Apple's Anderson said operating expenses should rise, while margins slip. The company plans on taking an unspecified fourth-quarter charge related to jobs cuts at a manufacturing unit.

Investments in Earthlink (ELNK: Research, Estimates) and Akamai Technologies (AKAM: Research, Estimates) lost money. Apple said it may take a fourth-quarter write-off for those.