Speciality plastic and fibre products supplier Filtrona said trading in the first quarter of 2011 was in line with management expectations, though judging by the share price reaction, the market was pleasantly surprised. Company revenue rose 8% from the first quarter of 2010, or by 9% on a constant exchange rates (CER) basis.Revenue in the Protection & Finishing Products division was up 21% year on year (23% using CER), while the Porous Technologies arm's turnover advanced 5% (CER: 8%).Coated & Security Products revenue rose 9% (CER: 10%), leaving Filter Products as the only division letting the side down, with a 4% slide in turnover.Net debt as at 2 April was £87m.Broker Panmure Gordon said: "Top line growth was slightly below our expectations with Filters unexpectedly going backwards, though Protection & Finishing delivered much better growth on the back of better volumes. As a higher margin division than Filters this more than underpins our profit expectations, and should assist further decent progress both this year and next."With the share price at its current level the broker sticks with its "hold" recommendation. ---jh