The consolidated adjusted EBITDA margin was 4.5% in the third quarter of 2015.
Medical sales increased 28.7% from the third quarter of 2014, generating a segment EBITDA margin of 8.4%.
Executive Chairman Peter Leys commented, Our unique capability of combining software and printing services positioned us for another successful quarter. All three of our segments 3D Printing Software, Medical and Industrial Production generated impressive revenue gains of 42.0%, 28.7% and 27.7%, respectively. In addition to these strong top-line gains, after three quarters of significant post-IPO investments in S&M and R&D, all of our segments again generated positive EBITDA.
We continue to see encouraging growth in the fourth quarter and are reaffirming the revenue guidance we previously provided for fiscal 2015. As a result of the markets positive response to the strategic projects we launched in each segment, in particular the roll out of our build processor and AMCP backbone, the opening of our pre-operative planning and surgical guide platform to new partners and the securing of partnerships for high-end manufacturing projects, we are accelerating certain investments into 2015. In addition we have been executing our transition from perpetual to annual software licensing successfully, which has resulted in higher levels of deferred revenue. For these reasons, we are reducing our Adjusted EBITDA guidance for 2015.
Third Quarter 2015 Results
Total revenue for the third quarter of 2015 increased by 30.5% to 25,883 kEUR compared to 19,833 kEUR for the third quarter of 2014, driven by strong gains in our 3D Printing Software, Industrial Production and Medical segments. Excluding revenue from OrthoView, which we acquired in October 2014, total revenue for the quarter increased 25.5%. Adjusted EBITDA decreased from 2,055 kEUR to 1,175 kEUR, reflecting ongoing investments. On a global basis, sales and marketing (S&M) expenses increased by 2,275 kEUR to 33.4% of total revenue. General and administrative expenses (G&A) increased by 1,198 kEUR to 15.3% of total revenue while research and development (R&D) expenses rose by 894 kEUR, to 17.6% of total revenue. The Adjusted EBITDA margin in the third quarter was 4.5% compared to 10.4% in the third quarter of last year.
Revenues from the 3D Printing Software segment, which offers a proprietary software backbone worldwide that enables and enhances the functionality of 3D printers and 3D printing operations,
increased by 42.0% to 6,303 kEUR for the third quarter of 2015 from 4,438 kEUR for the same quarter last year. Growth was fueled by our expanded product portfolio, strong growth in revenue generated with original equipment manufacturers (OEMs) and a significant increase in new license sales across all regions. Segment EBITDA increased to 2,157 kEUR from 1,518 kEUR while the segment EBITDA margin of 34.2% was even with last years period.
Revenues from the Medical segment, which offers both a medical software platform and a portfolio of medical devices and clinical engineering services, increased by 28.7% to 9,123 kEUR for the third quarter of 2015 compared to 7,090 kEUR for the same period in 2014. Excluding the impact of the October 2014 OrthoView acquisition, revenue increased 17.9% from the third quarter of 2014. Sales of medical software increased 59.0% to 2,779 kEUR from 1,748 kEUR, mainly due to the inclusion of OrthoView license revenue
Organically (excluding OrthoView), revenue from medical software licenses increased 15.4%. Annual licenses now represent 65.1% of new medical software license sales (excluding OrthoView) as compared to 18.1% in last years period. Revenues from the direct sale of our complex surgery guides and implants increased by 22% from the prior-year period. Revenue from our collaborated guide business increased 5.7%, as a result of a more diversified mix of partnerships. Segment EBITDA increased to 763 kEUR from 677 kEUR and the segment EBITDA margin fell to 8.4% from 9.5% compared to the third quarter of 2014
Revenues from the Industrial Production segment, which primarily offers 3D printing services to industrial and commercial customers, increased 27.7% to 10,457 kEUR for the third quarter of 2015 from 8,190 kEUR for the third quarter of 2014. Growth in the quarter was driven primarily by higher sales of end parts (including RapidFit and i.materialise), which rose 47.3% in the third quarter of 2015 from the same period in the prior year. Segment EBITDA rose to 799 kEUR from 753 kEUR while the segment EBITDA margin decreased to 7.6% from 9.2% for the same quarter of the prior year. Excluding the companys growth businesses, i.materialise and RapidFit, the segment EBITDA margin for the third quarter was 17.1% as compared to 18.8% for the same quarter of the prior year.
Gross profit was 14,702 kEUR for the third quarter of 2015 compared to 12,154 kEUR for the third quarter of 2014. The gross profit margin decreased to 56.8% for the third quarter of 2015 from 61.3% for the third quarter of the prior year. This decrease was largely due to a substantial increase in depreciation expense, including with respect to the 14 new printers that the company purchased over the past four quarters.
R&D expenses increased by 24.3% to 4,566 kEUR for the third quarter of 2015 from 3,672 kEUR for the same period in the prior year, reflecting continued investment with a number of active projects in various stages of development, across all segments. All of the companys R&D spending was expensed
S&M and G&A expenses were 12,613 kEUR for the third quarter of 2015 compared to 9,140 kEUR for the third quarter of 2014, an increase of 38.0%. The 3,473 kEUR increase was partially related to the inclusion of OrthoView and partially reflects a substantial increase in number of new employees in the sales and marketing organization of all three segments.
Net other operating income increased by 242 kEUR to 1,643 kEUR in the third quarter of 2015 from 1,401 kEUR in the same period of the prior year. Other operating income consists of withholding...