IBM is taking Amazon.com to court over allegations of patent infringement.

Seeking unspecified damages in two lawsuits, the company alleges that Amazon.com knowingly exploited its intellectual property by infringing on several patents that cover, among other things: the presentation of applications in an interactive service; the storage of data in an interactive network; the presentation of advertising in an interactive service; and the ordering of items from an electronic catalogue.

IBM first notified Amazon.com about the alleged infringement in September 2002, but claims Amazon.com hadn't wanted to engage in "meaningful discussions". Other companies license the patents in question, according to IBM.

Amazon.com declined to comment, saying that it had not yet received official notice of the suit.

The contested patents are at the heart of how Amazon.com operates, an IBM spokesman said. IBM doesn't resort to lawsuits very often, so the decision to take this step reflects how seriously IBM takes this matter, he said.

"Rather than build its business on its own technologies, Amazon has relied on IBM's innovations, unlawfully taking and using them for its business," IBM wrote in one of the complaints.

IBM is entitled to royalties on the billions of dollars in revenue that Amazon.com has generated through its "unlawful infringement" of the patents, one of the complaints states. IBM also seeks injunctive relief to prevent Amazon.com from continuing the alleged infringement.