Swiss Re managing director and chief executive Walter Kielholz spoke at this year's official conference.
Kielholz's speech, entitled Time for fundamental change, identified the challenges the industry was facing and advocated far-reaching change.
The speech was well attended and delegates noted that these more formal Monte Carlo events are growing in popularity.
Kielholz said: "We now look more at risk than opportunity - we do not look at the opportunity in risk."
He added that, since 11 September, the risk appetite in the world had drastically reduced.
On top of this, the frequency and severity of major claims was higher, premiums income was insufficient and capacity was unlikely to increase due to the uncertain financial environment, he said.
Kielholz said the industry must address this and other challenges by taking underwriting "back-to-basics" and improving risk and claims management.