Philip J. Angelastro
Executive Vice President and Chief Financial Officer at Omnicom Group
Thanks, John. And good afternoon. Thank you for taking the time to join us. fourth quarter results continued the momentum of the third quarter and helped us finish the year in a strong position, as it was pre-pandemic. We are in a stronger position to serve our clients in 2022 and beyond.
Let's begin with a brief look at our income statement on Slide 3. Growth in revenues and operating profit flowed through to net income for both the quarter and the year. Combined with our assumption of our share buyback program, we had 6% growth in diluted earnings per share. Dividends grew 7.7% in 2021 and we're pleased to resume this growth after maintaining our dividend payments throughout the pandemic.
Please turn to Slide 4 and we'll go through our results in more detail, starting with revenues. Our total revenue growth in the quarter was 2.6%, while our organic growth for the quarter was 9.5% or $358 million. The impact of foreign exchange rates decreased our revenues slightly in the quarter by just 30 basis points. However, if rates stay where they were at January 31, we estimate that the impact of foreign exchange rates will reduce our revenue by approximately 2% in both the first and second quarters of 2022.
The impact on revenue from our net acquisitions and dispositions decreased revenue by 6.6%. This was consistent with our expectations and is primarily the result of disposition activity from Q2 of 2021. We have also acquired some excellent businesses in key growth areas, which I will discuss later. Based on transactions completed to date, we estimate the impact of acquisitions, net of dispositions, will reduce our revenue by approximately 9% in the first quarter and by approximately 5% in the second quarter of 2022. And we expect positive acquisition growth in the second half of 2022.
Slide 5 presents the changes in our total revenues by business discipline. Advertising, our largest category, posted 4% organic growth in the quarter. Both our media agencies and our creative agencies contributed nicely to this growth. Precision Marketing grew 19.6% organically in the quarter and is now 8% of our total revenue. As John discussed, the businesses in this discipline are doing exceptionally well and have a great pipeline for their work in digital and marketing transformation consulting services, e-commerce, marketing sciences and digital experience design.
Commerce and Brand Consulting was up 12.4% with widespread strength across our larger agencies. In commerce, our agencies experienced strong growth although off a reduced pace. In brand consulting, we're seeing benefits and good activity in the technology sector and from corporate branding aimed at reputation, ESG and DE&I. Experiences growth in excess of 50% benefited from a return of some in-person events throughout the fourth quarter before the Omicron variant took hold. And we expect continued growth in 2022, although likely choppy, as brands look to engage with consumers in person.
Execution & Support was up 5.2%, with growth in the US businesses exceeding the performance of our businesses in Europe where our field marketing business was impacted by the new variant. PR was up 4.4 % and Healthcare was up 4.5%. Both of these disciplines reflected strong performance across our agencies. It's worth remembering that they performed relatively well throughout the pandemic. So we are pleased with the result.
Flipping to slide 6, you can see that we grew organically in each of our regions and growth came from most of our disciplines within these geographies. In the US, our 7.8% organic growth was slightly higher than the last quarter. Led by advertising media, as well as precision marketing, our growth remains over 20%. Also, results of our experiential business in the US this quarter, were quite strong as I mentioned.
Outside the US, growth was led by the UK and the Asia-Pacific region. The strong PR, media and commerce and consulting results in the UK and broad strength across the board in Asia. It's worth mentioning the strong organic growth of 48% from the Middle East and Africa, our smallest region.
Revenue in Q4 of 2020 was down over 35%. In Q4 2021, advertising media performance was strong. In this quarter's results, we're also positively impacted by experiential revenue related to the Dubai Expo which was initially scheduled for 2020.
Looking at revenue by industry sector on slide 7. Relative to full year 2020, there was a two-point increase in our revenue mix from technology clients, offset by a one point reduction in the revenue mix from pharma and health [Phonetic].
Let's now turn to slide 8 for a review of our operating expenses. Salary related service costs, our largest category increased by 11.1%. As expected, these costs, which include freelance support increased along with our increase in revenue, as did travel and entertainment costs, which aligns with the fact that our people are slowly going out in certain markets and meeting with clients in person. Next line [Phonetic] item, third-party service costs, were down 11.2%. They decreased by approximately $220 million from dispositions and were offset by an increase of approximately $100 million from growth in our businesses.
Occupancy and other costs, which are less directly linked to changes in revenue were up 4.2% year-on-year due to higher general office expenses as we return to the office, offset by lower rent and other occupancy costs, as we continue to use our spaces more efficiently. SG&A expenses were up 8.4% on a year-over-year basis due to an increase in marketing, professional fees and new business cost.
In total, our operating expense levels were up slightly less than 3% from fourth quarter 2020 to 2021. We're comfortable with this growth, because it is linked to the return to the pre-pandemic environment, as well as our continued revenue growth, new business opportunities, and investments for future growth.
If you turn to slide 9, you can see our operating profit growth and our margin performance. For the quarter, operating profit increased 1.3% and represented a 16.1% operating margin. This is a slight margin decline from the fourth quarter of 2020 when expense levels were well below normal. Our fourth quarter EBITDA change in margin performance was similar. For the full year, operating profit was up 37.5% with a margin of 15.4%. And EBITDA was up 35.4% with a margin of 15.9%.
As we look forward, while we expect to continue to see a return of certain cost to more normalized levels. We also expect that they will be offset in part by reductions in certain discretionary and infrastructure costs, resulting from new ways of working and efficiencies achieved during the pandemic. As John mentioned earlier, for the full year 2022, we anticipate delivering the same strong reported operating profit margin of 15.4% that we delivered in 2021. And as always, we will continue to focus on growing our operating profit dollars.
Let's now turn to our cash flow performance on Slide 10. We define free cash flow as net cash provided by operating activities, excluding changes in working capital, which are generally positive for us on an annual basis. Free cash flow of $1.8 billion grew 5.4%. We're pleased with the strength of this important metric.
Regarding our uses of cash, we used $592 million of cash to pay dividends to common shareholders and another $113 million for dividends to non-controlling interest shareholders. We maintained our dividend throughout the pandemic in 2020 and increased it by 7.7% in 2021 to a quarterly rate of $0.70 per share.
I'm going to discuss capital expenditures in two pieces. Our normal capital expenditure levels were unchanged from 2020. Additionally, in the fourth quarter of 2021, we had a very unique opportunity to purchase our primary office building in London for approximately $575 million. Subsequent to the purchase during the fourth quarter of 2021, we issued 325 million British pound sterling notes due in 2033, with an attractive 2.25% coupon. To give you some background, we have more than 5,000 people that work there for multiple agencies. It's our largest office building globally in our second largest market. We've been consolidating space in London for some time and have exited 31 buildings since 2015. London is a key market for our future and this building is in the Southbank area, west of London Bridge, near the Tate Modern. A culturally vibrant area of London, key to attracting and retaining talent.
Financially, it's an attractive opportunity for our business and we will avoid expected market increases on our rent that didn't compare favorably to outright ownership. The purchase of this building has not changed our capital allocation strategy and did not impact our credit rating. Acquisitions picked up relative to 2020 at $202 million. As we talked about last call, we are investing in the areas most important to our clients and therefore to our future revenue growth.
Two acquisitions in the fourth quarter of 2021 are highlighted on the back of this deck. Jump 450 media, our performance media agency that is now part of Omnicom Media Group. And BrightGen, the digital business transformation specialist that is a significant implementation partner for the sales force marketing stack. BrightGen is now part of our Precision Marketing Group.
And lastly, we ramped up our stock repurchases during the fourth quarter, bringing the year to $518 million. As you know, our pre-pandemic annual range was 500 million to 600 million. So we are solidly back on track with this important total return component for our shareholders. Our historical capital allocation has been very consistent, using our free cash flow for dividends, stock purchases, and acquisitions. We don't expect this change going forward, although we do see more opportunities for acquisitions, similar to those we completed in 2021. These tuck-in type acquisitions are efficient for us because the acquired agencies and their service offerings can contribute across our Group to serve an embedded base of clients and to help win new ones.
Slide 11 shows our credit and liquidity, notwithstanding that Sterling note I just mentioned. You can see that our other financing activities throughout the year lowered our outstanding debt from December 2020 to December 2021. At year-end, our total leverage was 2.4 times. In addition to the $5.3 billion of cash on the balance sheet at year-end, we also have a 2 billion US dollar commercial paper program to backstop our $2.5 billion revolving credit facility.
I'll end my prepared remarks today on Slide 12, which shows our strong return on invested capital of 33.4% for the fiscal year 2021 and 44.3% return on equity. Both of these took notable steps up from 2020 and remain very healthy indicators of the strength of our business and its attractiveness to shareholders.
At this point, operator please open the lines for questions and answers. Thank you.
