Oracle chief executive Larry Ellison is expected to blast arch-rival SAP for stealing its software and costing the US company billions of dollars of revenue when he takes the stand Monday in a trial that is enthralling Silicon Valley.

The German company has admitted that a subsidiary wrongly downloaded thousands of Oracle's software files but says it had been unaware of the violations.
Charles Phillips, who was Oracle's president until this past September, told the jury on Thursday that Oracle would have charged SAP at least US$3 billion to US$4 billion to license the software, which was supported by SAP'S now-shuttered TomorrowNow subsidiary.
SAP has admitted that TomorrowNow acted improperly and has accepted liability. But SAP and Oracle disagree sharply on how much SAP should pay in damages, and that will be left to the jury to decide.
Oracle is seeking unspecified billions, while SAP's lawyers have put the damages at US$40 million.
SAP, Europe's largest software maker, has agreed to pay Oracle US$120 million in return for a promise by the U.S. company to not seek punitive damages, sources said on Wednesday.
Phillips, who is currently the CEO of privately held Infor, said the trial is important to send a message to the industry.
"There's sort of an honour among warriors here that we can compete fiercely but we don't take each other's software," Phillips said.
An Oracle attorney said Ellison, Silicon Valley's richest person, would take the stand on Monday, an appearance that could provide plenty of fireworks.
Ellison has waited more than three years to bring SAP to court. He has been publicly flogging SAP and has now shifted his attacks to include Hewlett-Packard, which recently hired former SAP CEO Leo Apotheker as its new chief.
(Writing by Gabriel Madway; Editing by Derek Caney and Steve Orlofsky)