(Bloomberg) -- IRB Brasil Resseguros SA just lost its top executives, the latest chapter in a drama that’s been dominating chatter in Brazil’s financial circles.

Chief Executive Officer Jose Carlos Cardoso and Chief Financial Officer Fernando Passos have resigned, the company said in a regulatory filing Wednesday. IRB also said Werner Suffert, a former member of the board, will take over as CFO and interim CEO.

The shake-up comes a day after Warren Buffett’s Berkshire Hathaway Inc. said it’s not an investor in the firm, as had been reported in local media. The denial sent the stock plunging 32% Wednesday.

Brazil’s Eleven Financial Research said in a report that it took part in a conference call held by IRB on Monday. In it, the firm said, IRB executives said Berkshire had increased its stake through its Berkshire Hathaway International Insurance Ltd. subsidiary and touted a close relationship with Berkshire’s vice chairman of insurance operations Ajit Jain.

IRB Brasil, which had never gotten a sell-equivalent rating from analysts since its 2017 initial public offer, has lost more than half of its value since Feb. 2, when asset manager Squadra Investments outlined its short position in a 150-page report. Analysts at Citi downgraded the stock to neutral from buy Wednesday and slashed their estimates for 2021 return on equity by more than half.

The shares closed at 19.05 reais in Sao Paulo on Wednesday, 58% below the average price target for the next 12 months, according to data compiled by Bloomberg.

“We are no longer confident that we have a reasonable basis for valuing IRB,” Bank of America analysts led by Mario Pierry wrote in a report placing IRB under review. “Investors should no longer rely on our previous recommendation and estimates.”

--With assistance from Katherine Chiglinsky.

To contact the reporter on this story: Vinícius Andrade in São Paulo at vandrade3@bloomberg.net

To contact the editors responsible for this story: Courtney Dentch at cdentch1@bloomberg.net, Julia Leite

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