Hewlett-Packard Co. is suing former Chief Executive Mark Hurd to stop him from taking a job at rival Oracle Corp.

The complaint filed Tuesday in a California state court comes a day after Oracle hired Hurd as co-president to help lead the database software maker as it tries to muscle in on more of HP’s turf.
The lawsuit shows the growing rancor between the companies,  long-time partners that are now competing in the market for computer servers.

HP claims that Hurd wouldn’t be able to perform the job at Oracle without spilling HP’s trade secrets and violating a confidentiality agreement. Hurd signed such an agreement as part of a severance package from HP that could top $40 million.

The suit mentions that Hurd was responsible for preparing HP’s strategic plans and was privy to a “highly confidential” analysis of Oracle’s competitiveness against HP.