SAP is being sued by US software vendor ePlus for allegedly infringing three software patents.

ePlus specialises in enterprise cost management software and filed the lawsuit in April 18 in Virginia regarding three e-commerce technologies, patent numbers 6,023,683, 6,055,516 and 6,505,172.

In June, SAP filed an Answer and Counterclaims, arguing that the patent were invalid and denying any infringement. A trial date has been set for March 2006.

The patent suit is at least the second from ePlus this year. In February, it collected $37 million against e-commerce rival Ariba after initially seeking damages of up to $98 million.