For nearly 50 years, Everest has been a source of strength for our customers.
We have also further fortified our already strong capital base with a $1 billion senior notes offering completed on October 7.
This is very efficient long-term 30-year capital at a low 3.5% coupon.
Everest's strength is evidenced by our third quarter results for the group, where despite the high frequency of natural catastrophe activity, we achieved 16% gross written premium growth and improved attritional combined ratio of 85.8%, excluding cat and pandemic impacts, net investment income of $234 million, operating income profit of $97 million, net income of $243 million, book value per share growth of 7% from year-end 2019 or 9% adjusted for dividends, and a record shareholders' equity of $9.6 billion.
The underwriting loss for the quarter was driven by the previously announced $300 million in catastrophe losses.
This is in the context of an estimated $35 billion industry loss in the third quarter.
We also added $125 million to our COVID-19 loss provision, reflecting the ongoing nature of this event and our prudent reserving philosophy.
Excluding catastrophes and the pandemic impact, our attritional combined ratios for the group in each of our segments, Reinsurance at 83% and Insurance at 94%, improved year-over-year and are reflective of the earnings generating power of the Everest franchise.
On a nine-month year-to-date basis, Everest has grown 15% and delivered an 88% attritional combined ratio, excluding the pandemic impact.
Everest Reinsurance had 20% quarterly growth year-over-year.
Everest Insurance had solid execution in the quarter with continued underlying margin improvement over 2019 and 6% growth year-over-year, despite exposure reductions in certain lines given the current economic environment.
The attritional combined ratio, excluding the pandemic impact, improved to 94% for the quarter compared to 96% in the third quarter of 2019.
For the quarter, the main insurance growth drivers were continued rate momentum of plus 19% excluding workers' compensation, and plus 13% including workers' compensation.
Regarding the ongoing COVID-19 pandemic, the $125 million loss provision in the third quarter was comprised of $110 million for Reinsurance and $15 million for Insurance.
Our overall COVID-19 loss provision year-to-date is $435 million, of which 85% is IBNR.
For the third quarter of 2020, Everest reported strong net income of $243 million.
This is more than double the $104 million of net income for the third quarter of 2019.
On a year-to-date basis, net income was $451 million compared to $792 million for the first nine months of 2019.
Year-to-date, net income included $67 million of net after-tax realized capital gains compared to $90 million in the first nine months of 2019.
We also had Q3 catastrophe activity of $300 million, pre-tax and net of reinsurance and reinstatement premiums.
And we added $125 million COVID-19 pandemic loss provision.
Year-to-date, our COVID-19 provision stands at $435 million.
The group experienced an underwriting loss in Q3 of $115 million due to the elevated level of natural catastrophes in the quarter as compared to an underwriting loss of $28 million in 2019.
On a year-to-date basis, gross written premium was $7.7 billion, up $1 billion or 15% compared to the first three quarters of 2019.
This reflects balanced and diversified growth in both segments, with Reinsurance up 15% and Insurance up 15% compared to last year.
During the third quarter of 2020, the company reported $300 million of catastrophe losses.
The after-tax basis amount was approximately $240 million.
On a year-to-date basis, the results reflected net pre-tax and net of reinstatement catastrophe losses of $345 million compared to $335 million during the first nine months of 2019.
Excluding catastrophe losses and the impact from the COVID-19 pandemic, the comparable combined ratios were 85.8% for Q3 2020 and 87.1% for Q3 2019, an 88% through the first nine months of 2020 and 87.7% for the first nine months of 2019, mostly attributable to the Reinsurance business mix changes.
Excluding the pandemic loss estimate, the group attritional loss ratio for the third quarter of 2020 was 59.3%, down from 59.7% compared to Q3 2019.
Excluding the pandemic loss estimate, the group attritional loss ratio for the first nine months of 2020 was 60.2%, up from 59.5% for the first nine months of 2019, primarily due to the continued change in Reinsurance business mix year-over-year.
For the Reinsurance segment, the Q3 2020 attritional loss ratio, excluding the pandemic loss estimate, was 57.5%, essentially flat from 57.6% in Q3 2019.
Year-to-date, it stood at 58.5%, excluding the pandemic loss, up from 57.5% for the first nine months of 2019.
The Reinsurance division has $323 million of year-to-date operating profitability, given its $294 million of year-to-date net investment income.
For the Insurance segment, the Q3 2020 attritional loss ratio, excluding the impacts from the pandemic, was 64.8%, down from 65.9% in Q3 2019.
Year-to-date, it stood at 65.2%, down compared to 65.6% for the first nine months of 2019.
The Insurance division has $62 million of year-to-date operating profitability, given its $126 million of year-to-date net investment income.
The Q3 group commission ratio of 20.2% was down compared to the prior year Q3 level of 23.3%.
The group commission ratio of 21.7% year-to-date was down compared to the prior year figure of 23%, largely due to the same reasoning.
The group expense ratio remains low at 6.1% for the first nine months of 2020, in line with our expectations.
Q3 investment income increased strongly to $234 million versus $181 million for Q3 2019.
For investments, pre-tax investment income was $420 million year-to-date as compared to $501 million for the first nine months of 2019.
The fixed income portfolio generated $408 million of investment income year-to-date compared to $383 million for the same period last year.
As expected, net investment income increased substantially as we recorded $89 million quarter-to-date of largely fair market value adjustments of our limited partnership investments in this line.
The pre-tax yield to maturity on the investment portfolio was 3.1%, diminishing from 3.4% one year ago.
We continue to hold a well-diversified, high credit quality bond portfolio with conservative duration at approximately 3.5 years.
The current overall fixed income reinvestment yields are averaging approximately 2%.
Other income and expense included $38 million of foreign exchange gains during the first nine months of 2020 compared to a loss of $44 million for 2019.
Regarding income taxes, our effective tax rate on operating income was minus 0.1% through Q3.
There is a year-to-date tax benefit of $31 million related to the CARES Act that we reported in the first quarter.
Excluding this benefit, the effective tax rate on year-to-date operating income would be 8.9%.
Along with growth and profitability, positive cash flow was a highlight this quarter as we generated record operating cash flows of approximately $1.1 billion for the third quarter of 2020 compared to $633 million in Q3 2019, reflecting the strength of the growth in premiums in 2020 compared to 2019.
Everest solidified its very strong capital position in the aforementioned opportunistic $1 billion senior notes offering in early October with a low coupon of 3.5% and 30-year tenure under very favorable market conditions.
The debt leverage ratio pro forma for Q3 stands at 15.1%.
Shareholders' equity for the group was $9.6 billion at the end of the third quarter, up from $9.1 billion at year-end 2019.
The increase in shareholders' equity in the first nine months of 2020 is largely due to the $451 million of net income; the mark-to-market impact on the fixed income assets, which increased by $349 million from December 31, 2019 plus $387 million of paid dividends and share buybacks.
Net book value per share stood at $239.98, up 7% from year-end 2019, or plus 9.3% when adjusted for dividends.

Summary:
Everest's strength is evidenced by our third quarter results for the group, where despite the high frequency of natural catastrophe activity, we achieved 16% gross written premium growth and improved attritional combined ratio of 85.8%, excluding cat and pandemic impacts, net investment income of $234 million, operating income profit of $97 million, net income of $243 million, book value per share growth of 7% from year-end 2019 or 9% adjusted for dividends, and a record shareholders' equity of $9.6 billion.