A U.S. investor who has backed hedge fund managers from John Paulson to Kyle Bass is pushing into Europe to offer managers an unusual choice: They can take a bigger share of profits with the catch that they risk losing all their money if the bets go awry. New York-based Prelude Capital Management, which specializes in a niche offering called first-loss funds, has hired former Bank of America Corp. prime brokerage executive Adam Karp to lead its expansion within Europe, according to people with knowledge of the matter.