UK-based retail chain Marks and Spencer on Monday became the latest firm to pull its online advertising from Google platforms over fears it is appearing next to extremist content.
It follows a UK government decision to remove its adverts from YouTube -- which is owned by Google -- after it emerged they had appeared alongside content from supporters of extremist groups, the BBC reported.
RBS, Lloyds and HSBC also announced similar moves over the weekend.
Google has said it does not always "get it right" and will improve.
The move follows a recent investigation by The Times, London, which found adverts from a range of well-known firms and organisations had appeared alongside content from supporters of extremist groups on the YouTube video site.
An ad appearing alongside a video earns the poster about 6 pounds ($8) for every 1,000 clicks it generates, meaning brands may have unwittingly contributed money to extremists.
Last week, ministers summoned Google for talks at the Cabinet Office after imposing a temporary restriction on the government's own adverts, including for military recruitment and blood donation campaigns.
Others such as fastfood chain McDonald's, beauty giant L'Oreal and luxury carmaker Audi, as well as the BBC, the Guardian and Channel 4, have suspended their advertising on both Google's search engine and YouTube site.
Sky News and Vodafone are also considering suspending their ads.
Image: Elliott Brown