The UK accounts for the 39 percent of Europe's online advertising spending. This makes UK the biggest online-advertising spender in Europe.
Figures compiled by the IAB Europe internet marketing trade body and analyzed by PricewaterhouseCoopers cover spending on display, classified and directories, search and email advertising.
The spending breakdown comes as a separate study by internet market analyst firm comScore found that websites run by mainstream UK newspapers and television stations are attracting far more visitors from overseas than the UK. That study means advertisers will need to devise strategies that take account of international readerships.
The online-advertising figures show that advertising spend across Europe hit €8bn last year, with the UK's slice amounting to €3bn. UK advertisers spent more than twice as much as the next largest spender, Germany, which accounted for 22 percent of the online advertising market.
Other analysts have predicted that spending on internet advertising will overtake radio for the first time next year.
The IAB Europe figures show that nearly half of all internet advertising spend across Europe was on search-related advertising, which took 45 percent of the total. Another 31 percent went on various forms of display advertising, with 22 percent on classifieds and directories and just 1.6 percent on email marketing.
Alain Heureux, President of IAB Europe, said: "These figures demonstrate without any doubt the significance of the European online advertising industry."
France accounted for 15 percent of Europe's online advertising spend last year, while the Netherlands spent 7 percent and Italy 6 percent of the total. Spain, Denmark, Belgium, Austria, Finland, Greece, Slovenia and Croatia together account for the remaining 12 percent of spend, totalling €927 million.