HP is suing Mark Hurd for violating his severance agreemment.

In the lawsuit against Hurd, HP says Hurd puts, "HP’s most valuable trade secrets and confidential information in peril," by accepting the job of President at Oracle.

On its company blog, HP says, "Mark Hurd agreed to and signed agreements designed to protect HP's trade secrets and confidential information. HP intends to enforce those agreements."

HP gave Hurd a $40+ million severance package when it fired him as CEO. This severance was presumably paid, in part, so Hurd wouldn't sue HP for wrongful termination.

But now it will give Hurd plenty of money with which to fight off HP's own lawsuit.

HP (and its shareholders) are probably feeling sick today. Oracle's stock is up 5% today, adding $6.23 billion to the market cap as of this writing. HP's stock on the other hand still hasn't recovered from Hurd's firing.

Hurd never signed a non-compete, but he did participate in many confidentiality agreements, which HP says make his job at Oracle impossible. "By working at Oracle, he cannot help but utilize and disclose HP's trade secrets and confidential information," alleges HP in its lawsuit.

Court Filing: HP Civil Complaint Against Mark Hurd