Our growth was especially strong in CRM Precision at 24%.
Our EBIT margins for the third quarter were 15.8%, which exceeded our 2020 margins and significantly outpaced the comparable period in 2019.
Net income and earnings per share for the quarter grew by more than 13% versus 2020 and were also significantly above our 2019 results.
We currently expect our full year organic growth to be approximately 9% and our full year EBIT margin to exceed our year-to-date margin for the nine months ended September 30, 2021 of 15.1%.
Omnicom Media Group acquired Jump 450 Media, a performance marketing agency.
Jump 450 will form the foundation for a dedicated performance media platform and business operation within OMG.
OSK has been in the top-10 of PR and comms agencies in Germany since 2008 and is the undisputed number-one for automotive.
Omni is a unique and powerful tool for us, and we now have over 40,000 Omnicom colleagues provisioned on the platform in over 60 countries.
Hundreds of our clients, including all of our top-20, utilized Omni.
We recently expanded the curriculum for our DE&I and OPEN2.0 strategies.
Slide 3 shows our third quarter improvement across our income statement, where our revenue growth and expense control drove an 8% increase in operating profit.
Our effective tax rate for the third quarter was 24.1%, down from our estimated effective rate for 2021 of between 26.5% and 27%.
This was primarily due to the favorable settlement of uncertain tax positions in certain jurisdictions, the impact of which was approximately $10 million.
These items positively impacted net income and diluted earnings per share, which was $1.65, up $0.20 or 13.8% versus Q3 of last year and up $0.33 versus the third quarter of 2019.
And finally, our $0.70 quarterly dividend, which was raised back in February, is 7.7% higher than last year.
Our total revenue growth was 7.1%.
Organic growth for the quarter was 11.5% or $367 million, which represents a significant improvement compared to Q3 of 2020 when the pandemic drove an organic revenue decline of 11.7%.
The impact of foreign exchange rates increased our revenue by 1.6% in the quarter as the dollar continued to weaken against most of our larger currencies compared to the prior year.
If FX rates stay where they were on October 15, we expect foreign exchange to decrease our reported revenue by approximately 1% for the fourth quarter and increase our reported revenue by 2% for the full year.
The impact on revenue from net acquisitions and dispositions decreased revenue by 5.9%.
Based on transactions that have been completed through September 30, 2021, our estimate is the net impact of our acquisition and disposition activity for the balance of the year will decrease reported revenue by approximately 7% in the fourth quarter and by approximately 4% for the full year.
Advertising, our largest discipline at 53% of our total revenues, posted 8.6% organic growth with very strong performance from both our creative agencies and our media agencies.
Please note that reported Advertising growth is down 0.4%, due primarily to the disposition of ICON in Q2 of 2021.
Our agencies focused on direct, digital and marketing transformation consulting services in our precision marketing discipline also posted strong organic growth at 24.3%.
CRM Commerce and Brand Consulting was up 18%, with our branding agencies leading the discipline's performance.
CRM Experiential was up 50%.
CRM Execution & Support was up 8.3%, reflecting a recovery in client spend compared to the prior year in our field marketing businesses, while our research businesses continued to lag.
PR was up 10.5%.
And finally, our Healthcare discipline was up 6.6% organically.
Outside the U.S., where total organic growth was 16%.
In addition, experiential growth outside the U.S. was over 100% in total.
In the U.S., we generated 7.7% organic growth, which was boosted by strong double-digit growth in our precision marketing and PR disciplines as well as solid growth at our healthcare agencies.
These costs increased by 7.6% in total, and they tend to fluctuate with the change in revenue.
We would also note that Q3 2020 salary and service cost amounts were reduced by reimbursements received from government programs of $68.7 million.
The tight labor market will create challenges in the near term that we are confident our management teams will overcome.
Third-party service costs, which fluctuate with changes in revenue, decreased 6.9% during the quarter due to our net disposition activity, primarily related to the disposition of ICON and partially offset by the organic growth in revenue as well as the effects of foreign currency exchange rate changes.
Occupancy and other costs, which are not directly linked to changes in revenue, were up 4.5% year-on-year or 2.9% when excluding foreign exchange rate translation impacts.
SG&A expense levels were up 5.3% on a year-over-year basis or 4.2% when excluding foreign exchange rate translation impacts.
With the strong revenue growth we discussed earlier, coupled with good expense control, you can see a notable improvement in our operating profit on a year-over-year basis at the bottom of the slide, up 8% for the quarter and 60.1% year-to-date.
For the third quarter, our operating profit margin was 15.8% as expressed in terms of our reported total revenues.
Lastly, on this slide, our reported EBITDA for the quarter was $560.3 million, up 7.4% for the quarter and 56.3% year-to-date.
Let's now turn to our cash flow performance on Slide 10, where you can see that in the first nine months of 2021, we generated $1.2 billion of free cash flow excluding changes in working capital, a $114 million or 10% increase versus the same period last year.
Our total debt was down about $500 million since this time last year as we eliminated the extra liquidity we added early on in the pandemic.
We did this through the early retirement in Q2 of $1.25 billion of our 3.65% senior notes, which were due next year, partially replaced with the issuance of $800 million of 2.6% 10-year notes due in 2031.
As for our debt ratios, due to our overall operating improvement versus Q3 of 2020 and our recent refinancing activity, we've reduced our total debt-to-EBITDA ratio to 2.2 times and our net debt-to-EBITDA ratio to 0.4 times.
Both metrics increased substantially over the 2020 levels.

Summary:
Our EBIT margins for the third quarter were 15.8%, which exceeded our 2020 margins and significantly outpaced the comparable period in 2019.
These items positively impacted net income and diluted earnings per share, which was $1.65, up $0.20 or 13.8% versus Q3 of last year and up $0.33 versus the third quarter of 2019.
Organic growth for the quarter was 11.5% or $367 million, which represents a significant improvement compared to Q3 of 2020 when the pandemic drove an organic revenue decline of 11.7%.
The tight labor market will create challenges in the near term that we are confident our management teams will overcome.
Third-party service costs, which fluctuate with changes in revenue, decreased 6.9% during the quarter due to our net disposition activity, primarily related to the disposition of ICON and partially offset by the organic growth in revenue as well as the effects of foreign currency exchange rate changes.
Both metrics increased substantially over the 2020 levels.