Shares of media company Future plunged 14% after it said trading has remained challenging and group revenue for the six months to 31 March fell 2-3% from the same time last year.It added that trading profits continue to be affected by the structural shift to digital distribution, particularly in Future's largest segment, videogaming. Despite these trends, Future said it is encouraged by a strong return on previous investment from some digital and partnership products and believes that the it will benefit from accelerated organic investment.The group is therefore maintaining the planned investment in both the UK and the US, despite margin pressure, to ensure the group is well positioned for the future, it said in Friday's company statement.This reduces potential trading profits at the full-year by some £2m, it warned. However, the impact on pre-tax profits should be fully mitigated by reduced charges in the income statement for amortisation of intangible assets and for net finance costs.Future expects to maintain the interim dividend when this is announced in May. CJ