Reinforced polymer technology firm Fenner unveiled a 53 percent increase in pre-tax profit for the half year ended 29 February after bumper demand from its energy and mining customers.Underlying pre-tax profit increased to £48.1m while pre-tax profit rose to £41.7m from £26.6m the previous year. Revenue for the period swelled to £412m from £332.5m previously.The group said trading since February has been in line with company expectations.Chairman Mark Abrahams commented, "Trading was very strong in the first half as growth drivers in our core businesses remained positive, underpinned by continuing buoyant demand from mineral extraction and energy sectors."He added, "Notwithstanding the influence of the current macro-economic environment on some of our markets, our order book remains healthy, we are trading in accordance with expectations and we remain confident in our ability to continue to make progress in the second half of the year."Revenue and profits at both the Engineered Conveyor Solutions ("ECS") and Advanced Engineered Products ("AEP") divisions were at record levels and significantly ahead of the previous period.Underlining the group's confidence in future earnings, the interim dividend has been increased by 32% to 3.50p per share. CJ