Dell Inc., the world’s second-biggest personal-computer maker, posted profit that disappointed investors after orders from American consumers declined, pushing the stock down 8.1%.

American home PC purchases slumped 6% in the third quarter, signaling the company’s chief executive officer, Michael Dell, needs more time to woo back shoppers with the retail partnerships he struck this year. Yesterday Dell said it will incur more costs to revamp the operations and cut jobs.

“Wall Street is getting impatient,” an analyst at Endpoint Technologies Associates Inc. in Wayland, Mass., Roger Kay, said. “He’s not delivering as much profit as the Street would like to see.” Net income rose 27% to $766 million, or 34 cents a share. That missed the 35-cent average of estimates compiled by Bloomberg. Dell had beaten predictions in the two quarters before yesterday, and investors had pushed the shares up 10% in the past week after rival Hewlett-Packard Co. posted results that topped estimates.

Sales rose 8.5% to $15.6 billion. Year-ago profit was $601 million, or 27 cents a share.

Dell fell $2.29 to $25.85 in extended trading after closing at $28.14 on the Nasdaq Stock Market. The shares have advanced 12% this year.

Mr. Dell, 42, held a conference call with analysts today, the company’s first in more than a year. The PC maker suspended the calls because of an internal accounting probe, which led Dell to restate four years of financial results last month.

Mr. Dell returned to the top job in January after Hewlett-Packard pushed his company from its perch as the world’s top seller of PCs, and sales and profit growth slowed in 2006 to their lowest levels in four years. Consumers had criticized Dell for poor service and began flocking to Hewlett-Packard just as they began to buy more laptops, fueling sales growth at most PC makers.

Dell has since looked to retailers to revive revenue, abandoning his strategy of selling mainly over the phone and the Internet. This week he struck a deal with French retailer Carrefour SA, which trails only Wal-Mart in sales.

“They are not growing nearly as fast, especially against Hewlett-Packard, which is taking share,” an analyst at Atlantic Trust Private Wealth Management in San Francisco, Chuck Jones, said. “While the retail strategy is something that they might need to do, it’s going to be very tough to pull off.”

Hewlett-Packard has kept the top rank in PC sales for five straight quarters, helped partly by its own retail network. Shipments surged 33% in the calendar third quarter, compared with a 3.8% gain for Dell, according to IDC, a Framingham, Mass.-based researcher.

Seventeen analysts tracked by Bloomberg advise investors to buy Dell shares, while 13 recommend hanging on to them and two say sell.