Alleging "corporate theft on a grand scale," Oracle ( ORCL) has sued rival software maker SAP ( SAP), claiming corporate espoinage. In a 44-page lawsuit filed in the U.S. District Court for Northern California, the database giant claims Garmany's SAP illegally entered Oracle's computerized customer support systems to steal "thousands of proprietary software products and other confidential materials." In many cases, Oracle claims, SAP gained access to the Web sites by posing as legitimate Oracle customers. "We've just been notified of the lawsuit and Oracle press release, and until we have a chance to study the allegations, we're not going to comment," says Steve Bauer, an SAP spokesman. Oracle and SAP are locked in a battle to dominate the business applications market. While SAP still leads, Oracle has narrowed the gap in recent years, largely through an expensive acquisition spree that has seen it buy major vendors including PeopleSoft, Siebel Systems, Retek and most recently Hyperion ( HYSL).