Thank you, Albert, and good morning, everyone. As Albert noted in his comments, this was a challenging quarter for the company, but it also included strong core underwriting results. During the quarter, we incurred a net loss attributable to common shareholders of $73 million and operating loss of $65 million. High catastrophe and weather-related losses overshadowed the core underwriting results that continue to show improvement. The company produced a current accident year combined ratio ex-cat and weather of 92.4%, which was a more than 5-point improvement over the prior-year quarter.
As previously announced, the quarter pretax cat and weather-related losses, net of reinstatement premiums, were $240 million or 22.2 points, primarily attributable to hurricanes Laura and Sally, the Midwest derecho, wildfires across the West Coast of the United States, the Beirut port explosion and other weather events. I'll provide a bit more color on a couple of these events.
Hurricanes Laura and Sally were combined $120 million event for us, predominantly an insurance event, where we experienced approximately $100 million of insurance losses versus $20 million of reinsurance losses. The Midwest derecho was only an insurance event for us and contributed $45 million to our cat losses in the quarter. In the quarter, we kept our COVID-19 loss estimate steady at $235 million.
As a reminder, the COVID-19 loss provision is associated with property, event cancelation, A&H and pandemic coverages. And as of September 30, the vast majority of the loss provision is still IBNR and the paid amount is de minimis.
During the quarter, the FCA test case ruling was decided. We took this information into account as well as other data as we continue to monitor the level of our COVID loss provisions. While there was some movement between subclasses of business, we remain comfortable with the overall loss provision. I would remind everyone that COVID is an ongoing situation, and we will continue to rigorously and carefully monitor developments across all lines of business and establish reserves if and when appropriate.
Moving into the details of the group level. During the third quarter, we continued to see improvement in our underwriting results. Our current accident year combined ratio ex-cat and weather decreased by over 5 points as the repositioning of the portfolios in both segments starts to earn through. The consolidated accident year loss ratio, ex-cat and weather, of 58.5%, a decrease of over 3 points, with improvement attributable to both segments.
We reported essentially no net favorable prior year reserve development in the quarter. We observed adverse loss experience in our liability and professional lines, and this was offset by favorable releases in some of our short-tail lines. In these times of social inflation, COVID and economic uncertainties, we believe it is appropriate to maintain a prudent approach to our reserves and to stay consistent with our strategy, which is to take bad news early and good news only after it has been confirmed. The consolidated acquisition cost ratio was 21.1%, a decrease of 1.4 points compared to the third quarter of 2019, and again, this was attributable to both segments. The consolidated G&A expense ratio was 12.8%, a decrease of 0.6 of a point compared to the third quarter of 2019.
The total general and administrative expenses decreased by $18 million. As we have discussed in previous quarters, due to the pandemic, we continue to experience lower run rate expenses in a number of areas. The temporarily lower run rate is helping our G&A ratio by about 1 point this quarter.
Moving on to fee income from strategic capital partners, this was $16 million for the quarter compared to $18 million in the prior year quarter. The decrease is due to lower profit commissions.
We'll now discuss the segments. Let me start with insurance. During the quarter, our current accident year combined ratio ex-cat and weather, for insurance, decreased by over 7 points as the repeat positioning of the portfolio continued to earn through. The insurance segment reported an increase of gross premiums written of $41 million or 5% for the third quarter. The increase principally came from good growth in professional lines, accident and health and aviation, largely attributable to new business and favorable rate changes.
This was partially offset by decreases in liability, marine, credit and political risk due to less opportunities driven by the economic climate as well as the runoff of our discontinued lines. The current accident year loss ratio ex-cat and weather decreased by 3.5 points in the quarter compared to the third quarter of 2019. This was due to the impact of favorable pricing over loss trends as well as the improved loss experience in the short-tail lines, largely associated with the repositioning of the portfolio and the exit from certain product lines.
With respect to the longer tail lines, notably professional lines and liability, given the uncertainty of the current situation, we are prudently not reflected the majority of excess rate over trend pricing in our expected loss ratios.
Let's now move on to the reinsurance segment. During the quarter, our current accident year combined ratio ex-cat and weather decreased by 2.7 points, again, as we reposition this portfolio and it continues to earn through. Reinsurance segment gross premiums written of $395 million for the third quarter was $116 million lower than the same period in the prior year. The third quarter is a lower GPW quarter for the insurance segment, typically representing only 15% of the reinsurance gross premiums written in the year.
This year, the quarterly gross premiums written was impacted by our decision earlier in the year to exit the Middle East Accident & Health business and the engineering line of business, which we believe have a positive impact on the bottom-line results. In addition, gross premiums written decreased in motor lines due to premium adjustments and other timing effects. As we look year-to-date, the reinsurance gross premiums written is down 12%, and this is consistent with the trend we have seen earlier this year as we rebalanced our book with lower catastrophe, agriculture and credit and surety business.
The current accident year loss ratio, excluding catastrophe and weather-related losses, decreased by over 2 points in the third quarter compared to the same period in 2019. This was principally due to changes in business mix and improved performance in aviation, professional lines and liability lines. Net investment income of $102 million for the quarter was $14 million lower than the third quarter of 2019, primarily due to the decrease in yields.
Sequentially, we had a bit of a rebound in our alternative portfolio in the quarter as it produced $25 million of net investment income. Our current book yield is 2.3%, and our new money yield is 1.4%. The duration of our portfolio continues to be approximately 3.4 years. Diluted book value per share decreased by $0.34 in the quarter to $54.75. This was primarily driven by the net loss and common dividends declared, partially offset by net unrealized gains.
With that, I'll turn the call back over to Albert.