Though the figure has been adjusted down from the 4.1 per cent rise predicted in December, this is mainly because the 3.5 per cent rise in 2012 was higher than expected.
Global spend will then rise by 5 per cent during 2014 and 5.6 per cent in 2015, according to the ZenithOptimedia report.
Strong growth in emerging markets is expected to underpin the growth over the next three years, with markets in Eastern Europe and Central Asia, "fast-track Asia" and Latin America growing at 10 per cent a year.
Ad spend in North America is expected to rise at between 4 and 5 per cent a year while spend in Northern and Central Europe is expected to be static during 2013 before growing by 2 per cent in 2014 and 2015.
read more http://www.mediaweek.co.uk/news/bulletin/mediaam/article/1180368/?DCMP=EMC-CONMediaAMBulletin and http://www.campaignasia.com/Article/341433,adspend-in-asia8217s-fastest-growing-markets-to-grow-103-per-cent-zenithoptimedia.aspx?eid=21&edate=20130429&utm_source=20130429&utm_medium=newsletter&utm_campaign=daily_newsletter