The battle between Oracle and SAP for dominance of the business applications took a bizarre twist yesterday as Oracle filed a lawsuit in the US against its arch rival, accusing it of "corporate theft on a grand scale".

The lawsuit accuses SAP and its subsidiary TomorrowNow of "systematically" hacking into Oracle's password-protected customer support website and downloading copies of its proprietary software.

Oracle claims it was alerted to the alleged fraud in November when it noticed unusually heavy traffic on its Customer Connection support site for PeopleSoft and JD Edwards customers. It claims a subsequent investigation found that over 10,000 illicit downloads had occurred and that all the customers whose IDs had allegedly been compromised were about to become or had recently become, TomorrowNow customers.

TomorrowNow is a consultancy firm that SAP acquired in 2005. The company specialises in supporting the software of PeopleSoft and JD Edwards, both of which have since become Oracle subsidiaries.

TomorrowNow undercuts the cost of the vendor’s own support offering - a tactic that Oracle has itself employed in offering support for Red Hat Linux.

A spokeswoman for SAP said, "We have just been notified of the lawsuit, and have taken note of the Oracle press release. We are still reviewing the matter, and, until we have a chance to study the allegations, SAP will follow its standard policy of not commenting on pending litigation."