Ratings agency Standard and Poor’s has lowered the ratings of six cat bonds following the release of RMS v 11 US hurricane model.

Simultaneously, the agency lowered their ratings on six of the bonds and affirmed the ratings on the remaining four.

S&P placed 16 cat bonds on CreditWatch negative on April 18 because of the impact of the update of the RMS model. The bonds had been modelled on an earlier version.

The ratings agency said in a statement: “Although modelling companies periodically update their models, the impact on the probability of attachment from such update is typically minimal. However, in this instance, the probability of attachment increased significantly.”

S&P said it had since received updated probabilities for 10 of the 16 bonds but that the remaining six bonds will have their CreditWatch status resolved in the next two weeks.