Dutch digital map maker TomTom reported a 76 per cent drop in fourth-quarter net profit as demand for its satellite navigation devices (Satnavs) plummeted, and said it sees a further decline in sales this year. TomTom has struggled for months to overcome slumping demand for such gadgets, which are used by car and truck drivers, as consumers instead opt for free navigation software on their smartphones and tablet computers. The consumer PND unit, TomTom’s biggest division, is struggling to turn around sales and profits, while the other TomTom businesses are far from offsetting those declines. “The visibility in our core PND markets is limited as there remains great uncertainty about the rate of decline of customer demand for the category in the year ahead,” TomTom said in a statement. “This is exacerbated by an uncertain macroeconomic climate in our core markets,” it added. TomTom also sells real-time traffic services through its internet-connected devices and smartphone apps, mapping data to businesses, as well as navigation units which are built into cars, including various Renault, Fiat and Mazda models.