Attorneys for former New York Stock Exchange Chairman Richard A. Grasso argued Wednesday that Grasso had fulfilled his fiduciary duty to the exchange and should be allowed to keep his $187.5 million compensation package.

“[He acted] as a reasonably prudent person would act,” Gerson A. Zweifach, a Washington D.C.-based partner at Williams & Connolly who represents Grasso, said in oral arguments before a New York Appellate Division, 1st Department, panel.