A significant portion of the gross insured losses from the fourth-quarter California wildfires are expected to be ceded to various global reinsurance markets, reducing the net exposure of the domestic primary market, Fitch Ratings said.

Fitch anticipates losses to reach the higher end of the estimates of AIR Worldwide, Risk Management Solutions and CoreLogic Inc., based on individual public announcements. AIR Worldwide and RMS placed insured losses between $9 billion to $13 billion, while CoreLogic's estimate was at $15 billion to $19 billion.

Reinsurance treaties with aggregate loss triggers could be vulnerable to the November wildfire losses. But gross losses from the Camp and Woolsey/Hill fires have also been large enough for certain insurers to recover losses from occurrence-based catastrophe reinsurance layers, according to the rating agency.

Fitch expects limited or no ratings actions due to the wildfires. It maintained stable outlooks on both U.S. nonlife insurance and global reinsurance sectors and projects overall industry combined ratio of 99% for 2018, including catastrophe losses from the wildfires.

The timing of the losses in the fourth quarter could affect the reinsurance renewal discussions on Jan. 1, 2019, which are for primary companies that transferred fire losses to their risk transfer partners.