AOL launched a significant upgrade of AOL News on Tuesday, but it had to turn off some new features so that the site could handle a heavy flow of users.

AOL News, a news aggregation site, became slow and unavailable in the afternoon for what an AOL spokeswoman said was a "brief period of time".

At mid-afternoon, the site either didn't load or loaded very slowly for several IDG News Service staffers located in different parts of the US.

AOL expects to reinstate the removed features progressively this evening and during the day on Wednesday, the spokeswoman said. At press time, AOL News didn't seem to be experiencing any performance problems.

The redesign gave AOL News a blog format that combines traditional news sources, AOL programming and social news features, such as giving readers the ability to rate and share articles and post comments.

Some of the social news features had to be pulled off the site at different points in the morning and afternoon to accommodate heavy traffic, said Lewis D’Vorkin, senior vice president of AOL News & Sports.

He stressed that the revamped AOL News is in a beta phase, during which AOL is closely monitoring usage of all sections and features of the site and making the necessary adjustments.

"We had large traffic today, some big stories, so we removed some of those [social news] features to better the performance of the site," D'Vorkin said.

The site currently does have a feed from the company's Netscape social news site, which offers users a wide variety of interactive features.

Having a hot new Web site crushed by a flood of Web traffic is almost a point of pride with the Web 2.0 set, but a company the size of AOL should be able to do better, said Rich Miller, an analyst with Web analysis firm Netcraft Ltd. "They've got so much infrastructure and have launched large services before, so if they're having trouble I wouldn't be bowled over by their reliability," he said.

Asked if AOL was caught by surprise by the intensity of Tuesday's traffic, D'Vorkin replied that it was not. "Nothing surprises me and nothing catches me off guard," he said.

The AOL News redesign is groundbreaking as a "mass market" news site that adopts a blog format with a broad set of interactive, Web 2.0, social news features, he said. It brings together features that AOL has been testing and providing for several years, he said.

"We have developed a very unique site," he said. "It's exciting to learn and present news in a vastly different way."

Robert McMillan in San Francisco contributed to this story.