LONDON (Reuters) – Lloyd’s of London estimated net claims of $900 million for Hurricane Maria, which caused devastation in Puerto Rico last month, the specialist insurance market said on Monday.

Lloyd’s also revised down its net claims estimates for hurricanes Harvey and Irma, which hit the United States in recent weeks, to $3.9 billion from initial estimates of $4.5 billion.

Insurers and reinsurers are counting the costs of the three hurricanes, which together with earthquakes in Mexico and wildfires in California, are adding up to a heavy year for natural catastrophe losses.

Lloyd’s said it had already paid $900 million in claims for the three hurricanes.

“We are experiencing one of the most active hurricane seasons this century,” Jon Hancock, Lloyd’s performance management director said.

“While it is clear that these catastrophes will bear a heavy toll, the claims are spread across the entire Lloyd’s market, which has total net financial resources of 28 billion pounds ($36.92 billion).”

Hancock said that while Lloyd’s was cutting its earlier estimates for Harvey and Irma, “this is a developing situation and there continues to be a high degree of uncertainty around any claims estimate”.

(Reporting by Carolyn Cohn; editing by Maiya Keidan)