(Sharecast News) - Tracking systems provider Quartix expects full-year profits to exceed market expectations after a change in accounting practices and some "strong progress" in its core fleet business in the USA and France.Quartix, one of Europe's leading suppliers of subscription-based vehicle tracking systems and software, now sees adjusted earnings before interest, tax, depreciation and amortisation for the calendar year to come in 10-15% ahead of its previous £7.5m estimate.The AIM-listed firm revealed the change was largely due to its adoption of IFRS15, which also increased profit and revenues for 2018. Quartix said revenue and free cash flow were also expected to be "slightly ahead of market expectations" of £24.6m and £5.4m, respectively.Quartix added that management expectations for 2019 remained unchanged and that it expects to provide a post-year-end trading update in mid-January 2019.As of 0850 GMT, Quartix shares were flat on 240p.