Allied World Announces Fourth Quarter 2011 Catastrophe Loss Estimates ZUG, Switzerland, Jan. 20, 2012 /PRNewswire/ -- Allied World Assurance Company Holdings, AG (NYSE: AWH) announced today that it expects to record approximately $55 million to $65 million in catastrophe related losses and loss expenses in the fourth quarter of 2011. This includes an estimate of $40 million to $50 million from the flooding in Thailand which occurred in the fourth quarter 2011 and $15 million from increased estimates for global catastrophe events that occurred earlier in 2011. Allied World's loss estimates for these events are derived from preliminary information obtained from clients and brokers, a review of the terms of in-force policies and contracts, a review of outward reinsurance agreements and an analysis of our catastrophe modeling. Actual ultimate losses from these events may vary materially from the current estimates due to inherent uncertainties resulting from several factors, including the preliminary nature of loss data available, potential inaccuracies and inadequacies in the data that has been provided and the potential for catastrophe modeling inaccuracies.