(ShareCast News) - Media and events business Informa reported an 8.6% boost in revenue, which it said reflected disposal of some units and positive returns from new acquisitions.Shares in the company were up by 6.91% to 580p at 1315 BST after it posted £618.8m in first half revenue, up from £569.6m the year before.Informa's profit before tax was up by 21.65% to £121.9m from £100.2m.The company increased its first half dividend by 2.3% to 6.55p, as earnings per share lifted 8.5% to 21.8p.The company said its improved earnings were driven by growth in its Global Exhibition, Academic Publishing, Business Intelligence and Knowledge & Networking businesses.It said it would further invest between £30-40m in new initiatives this year.Informa said and its full year expectations remained unchanged not withstanding weakening of the US dollar against the pound.Investec kept a 'hold' rating on the stock and price target of 543p.Analysts said the margins were above forecast but boosted by its recent acquisition Hanley Wood.