Internet giants Google, Amazon, Microsoft and Taboola have reportedly paid AdBlock Plus to allow their ads to pass through its filter software.
The confidential deals were confirmed by the Financial Times, the paper reported today.
Eyeo GmbH, the German startup behind Adblock Plus, said it did not wish to comment.
So far more than 300 million users have downloaded its software, it said.
The add-on is free to download, with Eyeo generating revenue through its "whitelisting" programme. Companies can request their ads to be unblocked as long as they comply with AdBlock's "acceptable ads" policy. Large companies pay a fee for the service.
In December, French publishers were reportedly planning to sue Eyeo over the upstart's practice of charging money to stop blocking ads. According to L'Echos, the lawsuit is being considered by the French Internet Advertising Bureau and GESTE, a French publishers and content creators group.
Adblock has said only 25 per cent of Adblock Plus users are strictly against any advertising. It said those users can disable the feature.
However, in an online forum in November, one user responded negatively to the prospect of Taboola being whitelisted.
El Reg has approached Google, Amazon, Microsoft and Taboola for comment. However, according to the FT, Google, Amazon and Taboola have so far declined to comment.
In 2013, Google attempted to limit the damage of Adblock to its revenue streams by removing the Android app version of AdBlock Plus from its Play store. ®