Deidra Cheeks Merriwether
Chief Financial Officer and Senior Vice President at W.W. Grainger
Thank you, D.G. Turning to slide seven. You can see the high-level third quarter results for the total company, including 4% revenue growth on a daily organic constant currency basis. This number includes a headwind of roughly 50 basis points from the lap of a heightened level of service engagements in the prior year quarter. Within the period, we saw relatively stable gross margins across both segments, along with slight deleverage in High-Touch. This led to total company operating margins to be down 30 basis points in the third quarter, largely in line with expectations. Diluted EPS for the quarter of $9.87 was up $0.44 over the prior year period as higher sales were further aided by a lower share count in the current year.
Moving on to segment level results. The High-Touch Solutions segment continues to perform well, with sales up 3.3% on a reported basis or 2.5% on a daily organic constant currency basis. Results were driven by solid volume growth and improved price contribution within the segment. We also delivered growth across all geographies in the period local days, in local currency.
In the US specifically, we continue to see flat to positive growth in nearly all customer end segments, including persistent strong performance with contractors, warehousing and health care customers. For this segment, gross profit margin finished the quarter at 41.6%, down 10 basis points versus the prior year. In the quarter, we experienced an unfavorable product mix headwind as we lap the height level service engagements from the third quarter of 2023. This 60 basis point year-over-year headwind was largely offset by several small tailwinds, which included the lap of a onetime adjustment made to clear out unproductive inventory. Price cost for the quarter was roughly neutral.
SG&A costs this segment increased over the period as we continue to invest in demand generation activities, including marketing and seller head count, as well as normal wage inflation. Coupled with the softer top line, this led to SG&A deleverage of 30 basis points. Taking all this together, operating margin for this segment was down 40 basis points versus the prior year which was largely in line with expectations and remained at a healthy 17.6%.
Looking at market outgrowth on slide nine, using headline industrial production and producer price index, we estimate that the US MRO market grew between 2% and 2.5% in the quarter, with price once again contributing nearly all of the market growth. With our High-Touch Solutions US business growing at 2.6% organically, our mathematical market outgrowth in the quarter was roughly 50 basis points in total. This includes approximately 200 basis points of volume outgrowth contribution for the quarter, netted with continued price headwinds when comparing our price contribution to PPI.
Volume outgrowth year-to-date is roughly 350 basis points, just shy of our 400 to 500 basis point outgrowth target. As we've discussed this year, we're currently in a cycle where the growth rate implied by the headline IP and PPI metrics used in our market model, is higher than a number of other external data points across the MRO landscape would suggest. This difference continues to cause noise in our share gain calculation.
Although we will not mathematically achieve our market outlook target in 2024, we when using our headline market model, remain pleased with returns we're driving across our outgrowth initiatives and are confident we're taking solid share in the current environment. We believe this market measurement dislocation will normalize over time, and we continue to target 400 to 500 basis points of outgrowth annually on average.
Now focusing on the Endless Assortment segment. Sales increased 8.1% or 11.5% on a daily constant currency basis which adjust for the impact of the depreciated Japanese yen. Zoro US was up 11.3%, while MonotaRO achieved 15.4% growth in local days, local constant currency. At a business level, Zoro built on its second quarter performance and once again saw strong growth in the mid-teens from its core B2B customers. The headwinds from noncore B2C and B2C light customers continues to dissipate with sales to those customers roughly flat versus the prior year. The headwinds we've seen from this group are largely behind us, and we should go forward on even footing.
At MonotaRO, sales growth remains strong with enterprise customers, coupled with solid acquisition and repeat purchase rates with small and midsized businesses. On a reported basis, these results were partially offset by foreign exchange as the yen continues to be a year-over-year headwind.
On profitability, the operating margins for the segment increased 130 basis points to 8.8% with both businesses contributing leverage year-over-year.
MonotaRO margins remained strong at 12.4%, with DC operating efficiencies driving continued year-over-year improvement. At Zoro, operating margins were up 120 basis points to 4.3%, aided by solid operating leverage and a favorable onetime reserve true-up of roughly 70 basis points. These items more than offset an increase in marketing spend. Overall, we're encouraged by the strong progress we've made across the segment and remain on track to finish the year at or above our original expectations.
Now moving to the updated outlook for the full year of 2024. As D.G. mentioned at the beginning of the call, while the market has remained muted results have largely played out as expected for the year. With this, we're narrowing our full year 2024 earnings outlook. The narrow guide includes daily organic constant currency sales growth of between 4.5% and 5.25% and a diluted adjusted EPS range of $38.65 to $39.35.
The updated revenue outlook implies a fourth quarter 2024 daily organic constant currency growth rate in the mid-single-digits, which includes month-to-date growth in October of approximately 6.5%. This preliminary daily organic constant currency sales growth rate for October includes roughly 200 basis points to 250 basis points of hurricane-related sales, meaning normalized month-to-date results are closer to 4% and 4.5%.
Our operating margin expectations haven't shifted much from our prior guide. If you were to squeeze the operating margins from the updated annual guide, it implies a seasonal sequential step down in the fourth quarter to just above 15% at the midpoint. Supplemental guidance has also been updated, including an increase of $150 million to our operating cash flow outlook at the midpoint.
As a note, we've lowered our full year 2024 tax rate assumption to approximately 23.2% or 80 basis points less than the prior guide, which implies our fourth quarter tax rate somewhere between 20% and 21%. This reflects anticipated favorability in the fourth quarter as we adjust audit reserves from prior year tax returns and execute various tax planning strategies.
Full year foreign exchange rates have also been updated in the revised outlook. Overall, the year has played out largely as expected, and our updated earnings guidance remains within the original ranges we communicated at the beginning of the year. We look forward with confidence in finishing the year strong.
With that, I'll turn it back to D.G.
