Shares in graphene producer Directa Plus (LON:DCTA) fell over 20 percent in early trading on Friday, after the company announced the trebling of its pre-tax loss.

In its full year results for the 12 months to December 2016, Directa Plus reported an 89 percent revenue increase from graphene sales, excluding Mobile Decontamination Units (MDU), to 0.74 million euros, up from 0.39 million euros in 2015.

However, adjusted loss after tax for the full year increased to 4.1 million euros, up from a 1.7 million euro loss in 2015.

Looking ahead, the firm said “deepening engagement with existing and potential customers to provide more comprehensive solutions will mean timeframe to adoption will be up to 12 months longer than previously anticipated.”

It added: “As a result, and together with the now expected slowdown in volumes in 2017 into tyre segment and the time required to conclude the ongoing discussions on rental or sales of MDUs, the Group now expects a significant reduction in anticipated revenues for 2017.”

Shares in Directa Plus dropped dramatically on the news, currently trading down 21.55 percent at 71.00 (1123GMT).