David G. Barnes
Chief Financial Officer at Trimble
Thank you, Rob. Let's start on Slide five with a review of third quarter results. Third quarter revenue was $901 million, up 14% on a year-over-year basis. Currency translation added one percent and divestitures subtracted two percent for a total organic revenue increase of 15%. Gross margin in the third quarter was 58.7%, down 10 basis points year-over-year, reflecting several factors, including higher product and freight costs in our supply chain, offset by increased pricing and lower discounting. Adjusted EBITDA margin was 25.9% down 90 basis points year-over-year, driven by higher operating expenses and investments in the business. Operating margin was 23.8% down 40 basis points year-over-year, but still up over 300 basis points versus the pre-COVID third quarter of 2019. Operating expenses last year were unusually low in a number of areas, including compensation expense.
Net income dollars increased by 10% and earnings per share increased by $0.06 to $0.66 per share. Our third quarter cash flow from operations was $166 million and free cash flow was $156 million. Cash flow was down modestly year-over-year in the quarter as we are purchasing inventory in response to strong demand and supply chain shortages. Operating cash flow was up 23% on a year-to-date basis with a conversion ratio to net income above 1.1 times. Our net debt declined $88 million in the quarter, and our net debt to adjusted EBITDA ratio fell to 0.9 times. During the third quarter, we repurchased $100 million of common stock. At the end of the quarter, we had the entire $1.25 billion available on our revolving credit facility and approximately $513 million in cash. Our balance sheet is strong, and we are well positioned to invest in our business both organically and through acquisitions that will accelerate the implementation of our strategy.
Turning now to Slide six, I'll review in more detail our third quarter revenue trends. As mentioned earlier, our ARR was up eight percent in aggregate, and was up 11% organically on a year-over-year basis. The 11% rate excludes the impact of foreign exchange and our recent divestitures of Iron Solutions, Manhattan Real Estate Solutions and Construction Logistics. All three of these divested businesses had a recurring revenue component, but we're in areas outside of our strategic road map. Our nonrecurring revenue streams grew with hardware up 18% year-over-year and perpetual software growing 19%. Our hardware growth was driven by strong performance in civil construction, geospatial and agriculture. Our hardware growth contributed to perpetual software growth as some of our hardware offerings are bundled with perpetual software. From a geographic perspective, North American revenues were up 11%.
And Europe, revenues were up 18%. Asia Pacific was up five percent year-over-year, and the rest of the world was up 33%, driven principally by strong demand from the agriculture sector in Brazil. Next, on Slide seven, we highlight some of the key metrics we follow, and I'll start with ARR. While total company ARR grew 11% organically on a year-over-year basis, ARR, excluding transportation, grew at a mid-teens rate in the quarter. Net working capital, inclusive of deferred revenue continued to be negative, representing approximately minus two percent of revenue on a trailing 12-month basis notwithstanding an acceleration in purchases of component inventory during Q3. Research and development on a trailing 12-month basis was 15% of revenue and our deferred revenue grew 17% year-over-year. Our backlog at the end of the third quarter was $1.6 billion, up from $1.5 billion a quarter earlier and up over 30% year-over-year.
While growth in our backlog is an indicator of momentum in the business, it is also reflective of the shortages and extended delivery times that we are experiencing for many key components in our hardware products. Of our $1.6 billion in backlog, just under $340 million relates to our hardware offerings, up from about $100 million in hardware backlog a year ago and $38 million higher than the end of Q2. We expect supply chain constraints for many key components to extend well into 2022. Let's turn now to Slide eight for additional detail on each of the reporting segments. Buildings and Infrastructure revenue was up 12% on an organic basis. Revenue growth was strong in both our building and civil construction businesses, and organic ARR was up in the high teens in the quarter. Geospatial revenue was up 23% on an organic basis driven principally by strong performance in our core branded survey equipment.
Margins were up 60 basis points due to both revenue growth and operating cost control. Resources and Utilities revenue was up 23% on an organic basis. We experienced double-digit growth in each of our precision agriculture and positioning services offerings. Margins and resources in utilities contracted 330 basis points and were hardest hit by product cost inflation in the quarter. Financial results in transportation showed progression in a number of areas. Revenue was up three percent on an organic basis year-over-year, but grew less than we expected due to supply chain challenges in our operations and our customers' businesses. Margins expanded 410 basis points year-over-year. Turning now to Page nine for our updated outlook for the full year. We are raising our expectation for full year revenue with a new range of $3.59 billion to $3.64 billion representing growth for the full year in the mid-teens and single-digit year-over-year growth in the fourth quarter.
End market demand is even stronger than we thought it would be a quarter ago, but supply chain constraints will likely cause our backlog to remain at or above the increased levels from the end of Q3. ARR growth at the company level is trending as we anticipated, driven by strong bookings and subscription transition, and we expect organic ARR growth of greater than 10% in the fourth quarter and a strong entry point going into 2022. Gross margins in the fourth quarter are likely to be about flat sequentially with the third quarter. An increasing mix of software will have a favorable impact on sequential gross margin trends but this benefit will be offset by an anticipated decline in hardware margins. In aggregate, we now expect that the net impact of accelerating hardware cost inflation and our recent price increases will be modestly negative to hardware margins in Q4.
Building off our strong third quarter results, our outlook for operating margins continues to improve and we now expect operating margins for the full year 2021 will be above 2020. Operating margins in the fourth quarter of this year will likely be lower than the fourth quarter of 2020 driven both by higher hardware component costs year-on-year and by higher operating expense as opex was unusually low in 2020, and we are now ramping up investments against our strategy. Our outlook for full year earnings per share has increased to $2.61 to $2.69, representing growth of approximately 17% to 21% year-over-year. We continue to expect operating cash flow greater than 1.1 times net income and free cash flow greater than one times net income, reflecting the strong cash generative aspects of our business model.
I'd like to comment briefly on the outlook in the fourth quarter for our transportation segment. As Rob mentioned earlier, the leading indicators for this business are strong, with growing bookings of recruiting solutions, sequentially improving customer retention in our mobility business and increasing signs that our connected transportation strategy is resonating with customers. Nevertheless, factors related to the global supply chain and the extraordinary pressure on the transportation industry will negatively impact our business momentum in the short run. Our OEM business will be constrained by customer manufacturing challenges. And the aftermarket business will be slowed by the fact that trucking companies are reluctant to take assets off the road for technology upgrades at a time of high transportation prices and extraordinary asset utilization.
We believe that these constraints will be resolved over time, and we remain confident in the turnaround of this business, but the pace of improvement of revenue, ARR and profitability will be lower than we had earlier projected. With regard to 2022, we don't plan to give detailed guidance or our year-end earnings release, but we can characterize some of the drivers that we see now and the expected impact on reveNue, ARR and margins. Demand across our end markets remain strong, and we believe that strength will sustain at least through the end of 2022. Our customers need for digital solutions to optimize their workflows and has never been stronger, and these customers have the money and the desire to invest. We expect organic ARR growth to accelerate in 2022 and building off the momentum we have now and aided by continued model transitions and the growing sale of connected recurring solutions.
The supply chain environment remains our biggest challenge and that challenge is predicted to be with us for several more quarters. From a cost perspective, we anticipate that inflation in our hardware businesses will be sustained through the first quarters of 2022, driven both by higher component costs and higher cost of getting products shipped to our manufacturers and distribution centers. It is the goal of our pricing strategy to offset the impact of inflation on our hardware gross margins, and that pricing strategy continues to evolve. Rob referenced in his remarks, the investments we are making against our digital transformation. We anticipate that as we get through this investment cycle in 2022 and as our software businesses continue their transition to recurring revenue models, our operating leverage will be lower in 2022 than we expect over the longer term. The investments we are making in our digital transformation are at the core of unlocking the potential of our platform strategy, and we expect to end 2022 with business processes and systems that will accelerate our ability to transform the way we go to market and the way our customers do their work.
With that, I'll turn it over to the operator for Q and A.