Larry Ellison’s Guarantee Ups Warner Bros. Stakes to a New Level

Larry Ellison is throwing his personal fortune behind Paramount Skydance Corp.’s bid for Warner Bros. Discovery Inc., raising the stakes in a fiercely contested battle with Netflix Inc.

Both suitors moved on Monday to strengthen the financial backing for their offers, though they stopped short of increasing their bids. Netflix refinanced a portion of its planned $59 billion of debt as a way to ensure a lasting investment-grade rating — a key advantage it holds over the lower-rated Paramount.

Larry Ellison at the White House last January

Photographer: Aaron Schwartz/Sipa/Bloomberg

But it’s the personal guarantee of Ellison, the world’s fifth-richest person with a $246 billion fortune, that could ...