French reinsurer Scor’s Chief Executive Denis Kessler promised on Tuesday to release a strategic plan that would set new targets for the company, in a move to assuage an activist fund that questioned his role in a failed takeover process.

Kessler was responding a day after activist fund CIAM, which holds 0.9 percent of Scor’s capital, published a letter in which CIAM’s president Catherine Berjal criticized Kessler over spurning a proposed merger from French insurer Covea.

In that letter, Berjal said the blunt rejection by Kessler of Covea’s proposal, and a subsequent lawsuit lodged by Scor against Covea and Covea’s CEO, had led to a loss of over 900 million euros ($1 billion) in Scor’s market value.

Berjal’s letter asked whether Kessler had made the move to protect his job and “his personal interests to the detriment of the company’s shareholders.”

In a letter published on Tuesday, Kessler in turn threatened Berjal, saying that her comments could “constitute slander.”

Covea, Scor’s largest shareholder with an 8 percent stake, offered in September to pay 43 euros per Scor share, a 21 percent premium over the market price at the time.

The potential deal was viewed positively by investors, with the insurance industry undergoing a wave of consolidation as major players grapple with technology changes and the rise of new rivals from Asia.

Scor shares rose by more than 20 percent in the first two months after Covea made its offer before erasing almost all those gains when Covea dropped the merger plan last week.

Scor shares, which hit a peak of 43.59 euros in early November, were flat at 37.95 euros on Tuesday.

Kessler had rejected Covea’s bid, saying the price was too low. Scor’s board of directors also rejected the offer and eventually sued Covea and Covea Chief Executive Thierry Derez, who also held a boardroom seat at Scor.

Scor alleged Derez breached his legal and fiduciary duties as a company director, disclosed company secrets and used and disclosed confidential documents. Covea deny any wrongdoing.

After fending off the takeover bid and the dismal share performance, Kessler is now struggling to convince investors that he can oversee a rise in the value of Scor, which holds its annual shareholders meeting in April.

($1 = 0.8757 euros)