We continued to perform well in 2017, although we fell slightly short of our growth target of around 10 percent. We have succeeded very well in our main strategic objective of diversifying our business. Our net sales and profitability are no longer entirely dependent on individual customer relationships or customer segments. We have expanded into several customer segments and have increased our sales and activity in Central Europe, especially in Germany and the United Kingdom. The general economic recovery and the launch of investments were particularly evident in the industrial electronics customer segment, which saw the strongest growth. Last year, the sales of the security and defense electronics customer segment also developed strongly. In Aspocomp's latest customer segment, testing semiconductor components, we nearly triple our sales.
We posted our highest sales in the last quarter of the year, EUR 6.2 million (EUR 6.6 million 10-12/2016), but fell clearly short of the high sales in the reference period. January-December net sales amounted to EUR 23.0 million (EUR 21.6 million 1-12/2016), representing a year-on-year increase of 6.2 percent. Growth in net sales was slowed by the weakening of the US dollar. The comparable exchange rates had a negative impact of about EUR 0.17 million on net sales. The order book grew slightly and amounted to EUR 2.5 million at the end of the year (EUR 2.4 million 12/2016).
Fourth-quarter profitability fell behind the exceptionally strong reference period. The operating result for October-December amounted to EUR 0.3 million (EUR 0.8 million 10-12/2016). The full-year operating result grew by 10 percent to EUR 0.8 million (EUR 0.7 million 1-12/2016). The operating profit margin improved slightly and was 3.3 percent (3.2% 1-12/2016). Cash flow improved significantly from the previous year and amounted to EUR 0.8 million (EUR 0.1 million 1-12/2016).
Thanks to the EUR 10 million investment project to develop the company’s Oulu plant, which was announced in December, and the outsourcing of Asian volume production services, Aspocomp expects to grow significantly faster than the market at an average rate of 10 percent a year. The cornerstones of Aspocomp's growth include, for instance, next-generation 5G telecommunications and government networks, the e-revolution in the automotive industry, the development of testing requirements for semiconductor components as well as the spread of artificial intelligence and mechanical applications in the industry.
Espoo, February 15, 2018