Company spokeswoman Patty Smith said the downtime had to do with the company's network connection and was not caused by hackers. She declined to give further details, saying simply that Amazon engineers had fixed the problem.
"We occasionally have problems from time to time," Smith said. "The important thing is this was not any sort of external problem."
The outage occurred as Amazon prepares to announce its quarterly results today. Yesterday, the Seattle-based company announced that Joseph Galli, its president and chief operating officer, had resigned to become chief executive of VerticalNet.
Amazon's site was down from about 9:45 a.m. PT until about 10:25 a.m. Visitors to the popular e-tail site either could not reach Amazon's home page or received a note from the company.
"We are temporarily closed," the note said. "We expect to be back soon. We apologize for the inconvenience and thank you for your patience."
As reported earlier by CNET News.com, a previous message on the site said the problem was being caused by an "internal error."