(Bloomberg) — Rates charged by reinsurers, which have been falling for most of the past decade, may decline more slowly this year, the head of Allianz SE's reinsurance division said.

"Our assessments show that rates in some parts of the market are reaching a level where they don't seem sustainable and don't justify the risk-reward," Amer Ahmed, chief executive officer of Allianz Re, said in an interview in Munich. "In January, some programs had to be re-priced to keep reinsurers from walking away. That shows that we are reaching a point where economics prevent further significant price reductions."

Reinsurers including Munich Re and Swiss Re AG help primary insurers shoulder risks. The rates they charge to backstop claims from catastrophes such as hurricanes and earthquakes, typically the most costly disasters, declined in seven of the last 10 years, according to the Guy Carpenter World Property Catastrophe Rate on Line Index.