His move followed reports in the Italian newspaper La Repubblica of a dressing room revolt against the Serie A club’s leadership.
Roma finished sixth and missed out a place in the Champions League.
Manager Eusebio di Francesco was sacked in March and replaced by interim boss Claudio Ranieri, while legend Daniele de Rossi left the club.
“I don’t think anyone at the club has been more disappointed, more depressed or more upset with how things have gone at Roma over the past 18 months than I have been,” said Pallotta.
The businessman’s 3,151-word letter, published on the club’s website, addresses a number of issues and he says he will “not be driven out”.
The 61-year-old says he can handle “being a target and a punching bag almost on a daily basis” for fan’s anger, but goes on to describe personal attacks against his family as “disgraceful and despicable”.
“It’s obvious to me that there are certain people who are unhappy that they can’t manipulate, blackmail or berate me enough to get me to sell the team,” wrote Pallotta.
“I understand the history of almost 3,000 years of Rome and I know how this works. If people think they’re going to drive me out, it’s just not going to happen.”
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