The deal builds on a marketing agreement signed in 1999. AOL will use a broad range of HP's products and services, such as software, support, high-end servers and workstations.
HP, in turn, has signed a "multimillion-dollar" contract to market its products across several of AOL's online brands, including Netscape, Spinner.com and ICQ.
In separate news, AOL announced that its membership had passed the 30m mark, with 6m members outside the US.
The company said that overall subscription had doubled in the past two-and-a-half years.