Axel Springer has told the readers of Germany's most popular online news site to turn off their ad blockers or pay a fee as Europe's biggest newspaper publisher steps up efforts to protect advertising income.

Readers of Bild.de, the Web version of Europe's top-selling newspaper, have to disable programs that prevent ads or pay 2.99 euros ($3.40) a month to access content, Berlin-based Axel Springer said Tuesday. The fee will almost eliminate ads on the site, offer faster load times and help protect quality journalism, the company said.

Increased use of ad blockers is jeopardizing advertising revenue for online journalism, and Axel Springer is responding by testing the fee, Donata Hopfen, chairwoman of the Bild Group management board, said in the statement. Bild.de has more than 16 million unique users a month.

Axel Springer is targeting software that's used by about 200 million people around the world, costing publishers an estimated $22 billion this year, according to Dublin-based PageFair, a company started to counter ad blockers. Apple's latest mobile operating system allows iPhones owners to download web browser extensions that can prevent ads in mobile browsers. ProSiebenSat.1 Media and RTL Group earlier this year lost a lawsuit against Eyeo, which makes the Adblock Plus.

While 4oD and ITV don't let users watch content if they block ads, Axel Springer may be the first in Europe to offer a subscription alternative, the IAB said.

"All media needs to be funded one way or another and this solution puts the choice in the audience's hands rather than bypassing them altogether," David Frew, a manager at the IAB, said in an e-mailed statement.

-- Bloomberg News