Business software maker Oracle Corp. has added copyright infringement and breach of contract claims to a lawsuit alleging rival SAP AG trespassed on its computers to obtain secret product information so it would have a better chance to reel in new customers.

The documents filed June 1 in San Francisco federal court expands on a complaint that Oracle filed against Germany-based SAP in late March. The lawsuit charges SAP with “corporate theft on a grand scale” — blunt language that underscores the increasingly cutthroat battle between the two rivals.