Informa warned that half-year organic revenues at its Events and Training unit will be 'considerably' lower as the group continued to reduce volume to protect profitability in the face of weak demand. Despite this, the high variable cost base will mean that the impact on adjusted operating profit margin will be limited.The group's publishing businesses, Academic Information and Professional and Commercial Information, continued to grow. Informa expects ongoing action to improve efficiencies to result in an increased adjusted operating profit margin. Overall, the business publisher is still trading in line with forecasts with full year adjusted operating profit margins expected to be maintained at 2008 levels. Results will benefit from the strength of the US dollar and the Euro relative to 2008 levels, although the recent strengthening of sterling, if maintained, will reduce the positive impact in the balance of the year.Restructuring costs incurred to date in 2009 related to cost saving initiatives are expected to be approximately £10m with annualised savings estimated at about £20m."We remain confident about the group's future prospects and believe that the market positions of our leading brands and events leave us well positioned to grow significantly when world economies start to improve," said the group.Informa will announce its half year results on 28 July 2009.