Reed Elsevier chief executive Ian Smith has resigned after just eight months in the job as the publisher says its key professional information businesses have not escaped the downturn, while advertising and promotion markets are badly hit. "As expected, the trends in the first half of the year have broadly continued in the second half. The major professional markets, accounting for the majority of Reed Elsevier's business, are proving more resilient than most but not immune from late cycle pressures given the subscription nature of much of the revenue," said Reed.The Anglo-Dutch group, which raised about £800m in the summer, said Erik Engstrom, currently CEO of Elsevier, will take the top job with immediate effect."Ian has had the difficult task of leading Reed Elsevier during unprecedentedly turbulent economic times," said chairman Anthony Habgood. "The boards and I would like to thank him for his contribution in this respect and wish him well for the future."Reed said advertising and promotion markets remain particularly impacted by global recession, although its restructuring programmes are on track to deliver the targeted cost savings.It expects business trends seen in the second half to continue for the rest of this year and into 2010, especially with regard to late cycle effects in professional markets. Across the businesses, Elsevier continues to make revenue progress, although pharma promotion markets remain weak. LexisNexis has seen a "modest" decline in underlying revenues, while the exhibitions business is seeing overall revenue declines against a record year in 2008Things are still "difficult" at the business information unit, particularly in advertising markets. User revenues have "held up relatively well albeit behind last year.