AOL is betting heavily on ad-supported content as its future, after its spinoff from Time Warner last year. The strategy sets it apart from Google, which does not create any of its own content.

AOL also said on Tuesday that it had acquired 5min Media, a Web video syndication company that distributes a library of video clips from 1,000 media companies to other Web sites. It also bought Thing Labs Inc., which makes software for consumers to post online.

Mr. Armstrong told the TechCrunch conference audience that AOL would use TechCrunch as a pillar of its technology coverage. It will operate independently from Engadget, he said, but the two sites will use some of each other’s content.

TechCrunch, founded in 2005 by Michael Arrington, a lawyer, is widely read by technology industry insiders for its mix of breaking news and commentary  some of it bombastic. The company generates $10 million in annual revenue and $3.5 million in profits, he has said. It gets about 3.8 million unique visitors a month, ranking it as one of the more popular technology news sites. AOL’s Engadget gets about 7.3 million visitors a month.

Mr. Arrington, who is a major editorial voice for the site and a crowd-drawing fixture at his conferences, said in an interview that he planned to stay with TechCrunch for years, if not “all my life.” The agreement includes incentives to encourage the site’s staff to stay for three years.