An email from Apple CEO Steve Jobs has sparked a counter-claim from Sorenson Media against Apple.

A provider of video compression and streaming software, Sorenson Media filed for breach of contract, fraud and related claims against Apple in a federal court in San Jose California on Friday.

Initially, Apple sued Sorenson Media in April to prevent the company from licensing its video-compression software to Macromedia.

Sorenson Media's counter-claim rests on a February email from Jobs to James Lee Sorenson, Sorenson Media's CEO. The email allegedly states that Apple has exclusive rights to past but not future versions of software codecs produced by Sorenson Media.

Ed McGarr, vice president of sales and marketing at Sorenson Media, said: "Given the content of this email, which we have attached to our counterclaims, it is difficult to understand how Apple filed this lawsuit in the first place.

"Apple's lawsuit claims that Apple has exclusive rights to the very same things to which Mr Jobs admits that Apple does not have exclusive rights."

The counter-claim alleges that Jobs claimed to Macromedia that Apple had exclusive rights to Sorenson's Spark Codec, which was specifically designed for Macromedia's Flash MX product.