Philip Angelastro
Executive Vice President & Chief Financial Officer at Omnicom Group
Thanks, John. As you just heard, there are many exciting things underway at Omnicom and our success is driven by the investments we've made and continue to make in leading tools, platforms and capabilities needed to serve our current and future clients in a rapidly changing marketplace. The strength of our business model is that we continue to make these investments, while delivering solid financial results, as we did in the second quarter. Let's review our performance beginning on slide four.
Organic growth in the quarter was strong at 5.2%. The impact on revenue from foreign currency translation, as we expected, decreased reported revenue by 1%. If rates stay where they are currently, we estimate the impact of foreign currency translation will be negative 0.5% for Q3 2024 and for the full-year 2024. The net impact of acquisition and disposition revenue on reported revenue was positive 2.6%, due primarily to the acquisition of Flywheel this January and partially offset by the cycling of some smaller dispositions. Based on transactions completed to date, we expect the impact of acquisition and disposition revenue will approximate 1.5% for Q3 and for the full-year.
Now let's turn to slide five to review our organic revenue growth by discipline. During the quarter, Advertising & Media growth was once again quite strong at 7.8%, driven by improved performance in Advertising and excellent performance on our global media businesses. Precision Marketing grew 1.4%. While we saw a strong double digit performance at Flywheel, some of our project based consulting agencies within Precision Marketing encountered delays in client spending this quarter.
We do expect strong performance starting later in the second half, as new wins are brought online and project spend returns to a more normal level. Public relations returned to growth in the quarter and was up 1%. In the US, growth was approximately 4%, with a little more than half of that growth driven by US election related work. Healthcare grew 2% during the quarter, with consistent performance for both our US and international agencies. Branding & Retail Commerce declined by 3.8% as the environment for our branding agencies remains difficult. Experiential grew a strong 17.6%, driven primarily by client work related to the Olympics and Execution & Support grew 1.2%, the strong performance by our field marketing business, which was offset by our merchandising business.
Turning to geographic growth on slide six, we had a solid quarter across our regions. Our largest market, the US, grew 6.3%. Europe and the UK also posted strong growth. Asia Pacific, however, was flat on a challenging comparison to Q2 2023 at our Experiential business in China, while Latin America continued its strong growth streak. Slide seven is our revenue by industry sector for the quarter. Results year-to-date were generally stable as usual. Looking at our larger categories, we saw an increase in food and beverage and consumer products as a percentage of the total, driven by Flywheel's client mix, which was not part of our prior year revenue.
Now let's turn to slide eight for a look at our expenses. In the first quarter, salary related service costs grew with increased staffing levels, which primarily reflect our acquisition of Flywheel in January. However, these costs were down over 1.0 as a percentage of revenue year-over-year, reflecting ongoing strategic repositioning actions and changes in our global employee mix.
Third party service costs grew in connection with the growth in our revenue, especially in disciplines that have a higher level of these costs, such as Media, Experiential and Field Marketing. Third party incidental cost increased along with growth in our business and related out of pocket cost billed directly to clients. Occupancy and other costs increased year-over-year, mostly due to the Flywheel acquisition.
Our rent expense decreased and although total occupancy and other costs increased, they were flat year-over-year as a percentage of revenues. SG&A expenses increased year-over-year, primarily from increases in professional fees incurred in connection with our strategic initiatives. As a percentage of revenue on a constant dollar basis, however, SG&A levels were only up slightly.
Now let's turn to slide nine and look at our income statement in more detail. To start, in Q2, we took a repositioning charge of $57.8 million, which increased our operating expenses. This primarily reflects severance related to efficiency initiatives, including strategic agency consolidation in the smaller international markets of our advertising networks, the start of our centralized production strategy and other efficiency efforts. These initiatives continue and although we expect some additional steps to be taken in these areas in Q3, we expect them to be primarily self liquidating.
Table on this page shows the impact of this repositioning charge in the second quarter of 2024, as well as the net impact in Q2 of 2023 of the $72.3 million repositioning charge, as well as the gain of $78.8 million that were recorded in Q2 of last year. On a non-GAAP adjusted basis, EBITDA grew 5.5% and EBITDA margin was 15.3% versus the comparable 15.5% margin in the second quarter of last year.
As discussed last quarter, the relatively small decrease in margin includes the results of our Flywheel acquisition, as well as the related integration costs. Similar to last quarter, EBITDA reflects the $21.5 million add back to operating income, our amortization of acquired intangible assets and internally developed strategic platform intangible assets. We expect similar levels of amortization in the second half of the year. We also continue to expect our full year 2024 adjusted EBITDA margin to be close to flat with our 2023 adjusted EBITDA margin of 15.6%.
Moving down the income statement, net interest expense in the second quarter of 2024 increased $14.3 million to $41.7 million. The change was driven by a $5.2 million increase in interest expense due to higher outstanding debt from the Flywheel financing and a $9.1 million decrease in interest income due to lower average cash and short-term investment balances. Our income tax rate of 26% was close to flat compared to Q2 of 2023.
For the second half of 2024, we continue to expect our income tax rate to approximate 27%. Higher income from equity investments was offset by higher expense from earnings attributed to minority interest and despite a reduced diluted share count, reported earnings per share declined due to the repositioning costs, but on a non-GAAP adjusted basis increased 4.8% to $1.95.
Now please turn to slide 11. Free cash flow year-to-date is up 2.4% from last year. We define free cash flow as cash provided by operating activities, excluding changes in working capital. In Q2 2024, our working capital use followed its typical seasonal cycle and declined from Q1 to Q2 and our Q2 performance improved compared to Q2 of 2023 and the first half of 2023. We're making progress as expected and we continue to work towards our historically neutral levels of working capital.
Regarding our uses of cash, we used $279 million of cash to pay dividends to common shareholders and another $34 million for dividends to non-controlling interest shareholders. Our capital expenditures increased to $62 million, which as discussed on prior calls, we expect to be somewhat higher than last year, as we continue to invest in Flywheel and our strategic platform initiatives. Total acquisition payments were $829 million, which reflects the $845 million acquisition of Flywheel, net of cash required. There were no acquisitions in the second quarter.
Finally, our stock repurchase activity, net of proceeds from stock plans was $246 million year-to-date at $70 million in the quarter. Our expectation for the year is unchanged, with total repurchases reduced as a result of the Flywheel acquisition, approximately half of our historical average of $600 million. We continue to maintain our balanced approach to capital allocation with the competitive dividend, strategic acquisitions, share repurchases and an investment grade balance sheet.
Slide twelve is a summary of our credit liquidity and debt maturities. At the end of the second quarter of 2024, the book value of our outstanding debt was $6.2 billion, up over $600 million from funding a portion of the Flywheel acquisition during Q1 of 2024. Cash equivalents and short-term investments at June 30th were $2.7 billion, down slightly from last year.
We also have an undrawn $2.5 billion revolving credit facility, which backstops our $2 billion US commercial paper program. We continue to monitor the credit markets with regard to our $750 million of 3.65% senior notes that are due November 1, 2024. At this point, given where interest rates are and our financing activity early in 2024 and the anticipated refinancing, our current estimate compared to last year is that net interest expense will increase by approximately $7 million in Q3 and $16 million in Q4.
Slide 13 presents our historical returns on two important performance metrics for the twelve months ended June 30, 2024. Omnicom's return on invested capital is 20% and return on equity is 43%, both of which consistently reflect our strong performance and solid balance sheet.
I will now ask the operator to please open the lines up for questions-and-answers.