ZenithOptimedia has forecast that this year China will overtake the UK to become the fourth largest ad market in the world. ZenithOptimedia’s latest adspend predictions include 5.4 per cent growth in China this year. The agency also concluded that the worldwide advertising downturn is slowing down. The first quarter came in below forecasts, and the slide continued in the second quarter but at a lower pace. The agency has downgraded its global ad forecast for 2009 to a decline of 8.5 percent. It predicts a mild global recovery in 2010, with all regions to return to growth in 2011. Asia-Pacific, Central and Eastern Europe, Latin America and the rest of the world are likely to return to growth in 2010, followed by North America and Western Europe in 2011. According to the agency, internet advertising is forecasted to grow 10 percent this year, and reach 15 percent share of worldwide adspend.