Ackermann, a veteran of the hard-charging world of investment banking, prevailed, and the insurer told investors it was progressing “towards” the targets. That, along with a 17 percent drop in first-half net profit, prompted a near 4 percent fall in the share price.

The brief disagreement came less than two weeks before Wauthier killed himself, an event that has shaken Zurich Insurance, prompted Ackermann to resign, and focused attention on the former investment banker's management style.

In a typed suicide note, addressed, “To whom it may concern”, Wauthier described himself as demoralised after months of a new, more aggressive tone at Zurich under Ackermann, according to several people who have seen the letter.

Wauthier cited the encounter over the targets in the note.

Related Stories: Zurich Chairman Ackermann Resigns over CFO Suicide | Ackermann Cited in Suicide Note of Zurich CFO

Zurich has celebrated a “boring” image in the years since turning around from a near-collapse in 2002 following a ill-judged expansion strategy. Ackermann's blunt style was a huge change for Wauthier, used to a more consensual culture.

“He clearly had been feeling it for a very long time,” a source who has seen Wauthier's note told Reuters.

Ackermann declined to comment. Through a company spokeswoman, investor relations head Quin declined to comment.

Zurich said there was no evidence of a dispute between the two men over the company's outlook, and both the board and executive committee agreed on the company's message.

The insurer has launched an internal review to see whether Wauthier, a 53 year-old dual French-British citizen, had been put under undue strain but is still working on the details, a spokeswoman said.

People close to Ackermann acknowledged the difference of opinion over how the results should be presented, but said such debates are not unusual in a company like Zurich.

“If this was seen as unbearable pressure, then something else must have been wrong,” one of these people said.

NO WARNING SIGNS

Credited with transforming Deutsche Bank into an investment banking powerhouse, Ackermann, a Swiss national, took over the chairmanship of Zurich Insurance last year, determined to shake it up.

The 65-year old was much more involved in the day-to-day running of Zurich than past chairmen, according to sources.

Described by people familiar with his thinking as a “numbers person”, Ackermann used to hold one-on-one meetings with Wauthier, an unusual move for a non-executive chairman, and quickly immersed himself in details of the insurer's accounts.

A failure to set aside enough money to cover claims at its German arm had hit profits last year, and weak investment returns and heavy exposure to disasters in the United States had shaken investor confidence. The company's stock was underperforming European peers, and several top-level managers had left, giving rise to talk of a brain drain, sources inside Zurich say.

Several sources say there were no outward signs of tension at the meeting on the eve of the results announcement, and Wauthier didn't appear to be distressed.

Twelve days later, his body was found at his home, a former lakeside inn outside Zurich that the Wauthier family was in the process of renovating. His wife and two children were abroad at the time. They declined to comment to Reuters.

Colleagues and investors who met Wauthier in meetings in London days before he killed himself did not detect any warning signs. He responded to emails as recently as the day before his death, according to company sources.