Net sales in 4Q2018 were EUR 6.9 billion, compared to EUR 6.7 billion in 4Q2017. Net sales grew by 3 percent year-on-year, on both a reported and constant currency basis. The company’s topline performance reflects the strong competitiveness across our portfolio and that our strategy execution is tracking well. We maintained good momentum, with strong 5G customer engagement in all key markets, particularly strong performance in Nokia Software and solid performance in our enterprise business.
Non-IFRS diluted EPS in 4Q2018 was EUR 0.13, compared to EUR 0.13 in 4Q2017. Particularly strong execution in 4Q enabled us to achieve our full-year 2018 operational guidance, with year-on-year operating profit growth in Networks, as well as in Nokia Technologies on a recurring basis. Non-IFRS diluted EPS increased by EUR 0.02 year-on-year on a recurring basis, driven by our gross profit performance and continued operating expense reduction, partially offset by foreign exchange hedging and higher income tax expenses.
Reported diluted EPS in 4Q2018 was EUR 0.03, compared to negative EUR 0.07 in 4Q2017, primarily driven by lower income tax expenses and our gross profit performance, partially offset by lower one-time licensing net sales, foreign exchange hedging and higher financial expenses. In 4Q2018, net cash and current financial investments increased sequentially by approximately EUR 1.2 bn and we ended 2018 with a strong financial position. In 4Q2018, net cash from operating activities benefitted from strong seasonality and positive changes in net working capital. Consequently, recurring free cash flow for full-year 2018 was slightly negative.
In addition, cash taxes amounted to an inflow of approximately EUR 10 million, benefitting from a tax refund of approximately EUR 110 million. In the 4Q2018, net cash used in investing activities primarily related to capital expenditures of approximately EUR 170 million. This was partially offset by approximately EUR 80 million of cash inflows related to the sale of certain assets.