Dave Zapico
Chairman, and Chief Executive Officer at AMETEK
Thank you, Kevin. And good morning everyone. AMETEK had another outstanding quarter, with better than expected sales growth, strong operating performance, and earnings above our expectations. We established records for sales, EBITDA, operating income, and earnings per share in the quarter. Demand remained strong across our diverse set of end markets, leading to robust order growth, and a record backlog. While the global supply chain and logistics networks remain challenging, our businesses are doing a tremendous job navigating these issues and delivering results which exceeded our expectations. Given our results in the third quarter and outlook for the fourth quarter, we are again increasing our sales and earnings guidance for the full year. This strong overall performance reflects the exceptional work of all AMETEK colleagues, as well as the strength, flexibility, and sustainability of the AMETEK growth model. AMETEK's proven business model is central to our focus on creating a sustainable future for all stakeholders.
We are very proud of the important steps we're taking to further sustainability across AMETEK. And last week, we published our latest Corporate Sustainability Report to highlight our efforts in this area. This report provides information on our sustainability initiatives, the strong progress we have made, and the commitments we are making to create a better future. I welcome you all to read our latest Corporate Sustainability Report, which is located on our website. Now let me turn to our third-quarter results. Third-quarter sales were a record $1.44 billion, up 28% over the same period in 2020, and above our expectations. Organic sales growth was 17%, acquisitions added 11 points, and foreign currency was a modest benefit in the quarter. Overall orders in the third quarter were $1.55 billion, an increase of 37% over the prior-year period. While organic orders were up an impressive 30% in the quarter. We ended the quarter with a record backlog of $2.62 billion, which is up over $800 million from the start of the year.
Third quarter operating income was a record $338 million, a 25% increase over the third quarter of 2020, and operating margins were 23.4%. Excluding the dilutive impact of acquisitions, core operating margins were 24.7%, up 70 basis points versus the third quarter of 2020. EBITDA in the third quarter was a record $415 million, up 25% over the prior year, with EBITDA margins of 28.8%. This outstanding performance led to record earnings of $1.26 per diluted share. Up 25% over the third quarter of 2020, and above our guidance range of $1.16 to $1.18. We continue to generate strong levels of cash flow, with third-quarter operating cash flow of $307 million, and free cash flow conversion of 109% of net income. Overall tremendous results in a challenging operating environment. Next, let me provide some additional details at the operating group level.
First, the Electronic Instruments Group. Sales for AIG were a record $982 million, up 31% over last year's third quarter. Organic sales were up 15%, acquisitions added 16%, and foreign currency was a modest headwind. While growth remains broad-based, growth was particularly strong across our Ultra Precision Technologies, and our Power and Industrial businesses. AIG's third-quarter operating income was a record $245 million, up 20% versus the same quarter last year, and operating margins were 25%. Excluding acquisitions, AIG's core margins were excellent at 27.2% in line with prior year margins. The Electromechanical Group also delivered outstanding sales growth and excellent operating performance. Third-quarter sales increased 21% versus the prior year to $459 million. Organic sales were up 20%, and currency added one point to growth. Growth remained strong across all of the MG, with our automation businesses again delivering notably strong growth in the quarter.
EMG's operating income in the quarter was a record $115 million, up a robust 36% compared to the prior-year period. EMG's operating margins expanded an exceptional 270 basis points to a record 25%. Now, switching to our acquisition strategy. AMETEK has had an excellent year with a record level of capital deployment, leading to the acquisition of 5 highly strategic businesses. AMETEK is supported, approximately $1.85 billion on acquisitions, thus far this year, reflecting the strength of AMETEK's acquisition strategy and our ability to identify and acquire highly strategic companies. Our proven operating capability allows us to drive meaningful improvements across our acquired companies, resulting in outstanding returns on capital. Generating strong returns on capital deployed is critical to long-term sustainable growth, an important element of AMETEK strategy. AMETEK's strong cash flow generation continues to support our capital deployment strategy, our acquisition pipeline remains very active, our M&A team continue to work diligently, identifying attractive acquisition opportunities, and we expect to remain busy over the coming quarters.
We also remain focused on investing back into our businesses to support their organic growth initiatives, including in support of their new product development efforts. In the third quarter, we invested over $75 million in RD&E. And for all of 2021, we now expect to invest approximately $300 million or approximately 5.5% of sales. Through these investments, our businesses develop unique and highly differentiated solutions that help solve our customers' most complex challenges. One such example is a new product introduction from AMETEK Gatan. Gatan is a leading provider of direct detection technology, for Elektron microscopy [phonetic], supporting high-end research and materials and life sciences applications. Gatan recently introduced The Stela hybrid pixel camera, the only fully integrated hybrid pixel electron detector with the Gatan microscopy [phonetic] suite. This new product reinforces Gatan's leadership position, providing the highest quality TEM diffraction camera, allowing the user to perform 4D stem analysis for the rapid speed and high dynamic range. Gatan's new camera builds on a long history of disruptive and award-winning technology.
In August, The Stela Cameron was awarded the 2021 [indecipherable] today Innovation Award, and called one of the ten game changing products and methods. I would like to congratulate the team at Gatan for the recent launch of The Stela camera, and further support of important research applications. Now, let me touch on the supply chain issues. The global supply chain remains challenging, we see extended lead times for a broad range of materials and components with logistics issues, and labor availability adding to the complexity. While these difficulties exist, we exceeded our sales estimates for the quarter, and are navigating the challenging environment well, given our agile operating approach. The supply chain issues are leading to higher inflation. However, given our differentiation, we're able to more than offset this inflation with higher pricing, leading to a strong price inflation spread. While we expect these challenges will continue into 2022, we remain well positioned to navigate the issues, given the strength and flexibility of the AMETEK growth model.
Moving to our updated outlook for the remainder of 2021. Given our strong performance in the third quarter, and the continued strong orders momentum and record backlog, we have again raised our 2021 sales and earnings guidance. For the full year, we now expect overall sales to be up in the low 20% range, versus our previous guide up approximately 20%. Organic sales are now expected to be up low-double digits on a percentage basis over 2020, as compared to our previous guides of approximately 10%. Diluted earnings per share for 2021 are now expected to be in the range of $4.76 to $4.78, an increase of approximately 21% over 2020 is comparable basis, and above our prior guide of $4.62 to $4.86 per diluted share.
For the fourth quarter, we anticipate that overall sales will be up in the low 20% range versus last year's fourth quarter. Fourth-quarter earnings per diluted share are expected to be between $1.28 to $1.30 of 19% to 20% over last year's fourth quarter. In summary, AMETEK's third-quarter results were excellent. Our teams continue to execute, and our businesses are performing well. Our performance through a challenging environment shows the resilience and strength of the AMETEK growth model. The asset-light nature of our businesses, our leading positions in attractive niche markets, and our world-class workforce will continue to drive long-term sustainable success. The proven nature of the AMETEK growth model continues to drive long-term success for all of AMETEK's stakeholders. I will now turn it over to Bill Burke, who will cover some of the financial details of the quarter, then we'll be glad to take your questions. Bill.