Sept 12 (Reuters) - Federated National Holding Co
* Says estimates aggregate gross liabilities due to hurricane irma to be about $300 million for Federated National Insurance
* Says Federated National Insurance believes its losses,net of reinsurance,to not exceed first event pre-tax retention of $18 million-SEC filing
* Says monarch national believes its losses should not exceed first event pre-tax retention of $3.4 million due to hurricane irma
* Says monarch national currently estimates its aggregate gross liabilities associated with hurricane irma will be about $10 million Source text for Eikon: Further company coverage: