Eddie Hearn says he is "devastated" after Conor Benn made the "very painful" decision to leave Matchroom Boxing to join Dana White's Zuffa Boxing promotional company.
The 29-year-old had been with Matchroom since turning professional and beat long-time rival Chris Eubank Jr in a blockbuster rematch at Tottenham Hotspur Stadium in November, having lost their first bout in April.
Hearn, who learned of Benn's decision via email from the Briton's lawyer, said he made a "mistake" in trusting Benn because he "misjudged his character".
"I'm not going to sit here and hang Conor Benn out to dry but me, personally, I'm pretty devastated," Hearn told iFL TV.
"I've had a few days to digest what might happen. Maybe this interview is different to what it could've been a couple of days ago.
"It's not often I get shocked. And I blame myself because I forgot it was boxing."
Hearn said after reading the email he messaged Benn to say the pair should speak over the phone but Benn refused.
"I just felt that the loyalty we've shown would never, ever put us in this position," continued Hearn.
"I just felt that I never really needed to push Conor Benn to sign a new contract previously - and I probably could've got him to sign a new contract previously.
"I just felt... everything that we gave him, the loyalty that we gave him, the support we gave him would be enough to talk it through and get close to a number. But there wasn't really the interest.
"Very surprising. Very painful. But just another moment in life that you live and learn from."
Hearn was undecided when asked whether he could work with Benn again in the future. "He text me just after the announcement and I replied," said Hearn. "We had a few back and forths."
He also revealed he "had some very choice words" with Benn's manager, Keith Connolly.
In a statement on Instagram, Benn said he was "filled with excitement and hunger for what's ahead with Zuffa Boxing" while paying tribute to his former promoters.
"First and foremost I want to thank Eddie and the entire team at Matchroom for everything they have done for me over the past decade," wrote Benn, the son of former two-weight world champion Nigel.
"From guiding me when I first turned pro, to headlining stadium shows. They were not only with me for those highlight moments but stood shoulder to shoulder with me during the tough times."
Benn and Eubank Jr were originally set to fight in 2022 but the bout was called off when Benn failed a voluntary drugs test - twice testing positive for the banned substance Clomifene.
That sparked a two-year battle with authorities, before Benn's suspension was lifted in November 2024.
