Concerns over display of their ads alongside offensive videos prompted the move.
Google’s advertising crisis has deepened as some of the global biggest marketers move to freeze spending on running ads on YouTube and the internet giant’s display network.
The marketers cited concerns over the appearance of their ads alongside offensive videos as the reason behind the move.
Last week The Times newspaper reported that some advertisements had been placed alongside videos promoting terrorism or anti-Semitism on YouTube, leading to the controversy regarding Google’s ad operations.
Following this, both the UK government and the Guardian newspaper halted running ads on the video site.
Havas, the world’s sixth-largest advertising and marketing firm, also took down its UK clients’ ads from Google’s display ad network and YouTube, reported Bloomberg.
GlaxoSmithKline said: “The placement of our brands next to extremist content is completely unacceptable to us and we have raised our concerns directly with Google.”
The crisis intensified after US firms also pulled their ads from the network, resulting in loss of hundreds of millions of dollars in revenue for Google and YouTube.
AT&T and Verizon Communications said that they had halted non-search advertising spending with Google, while Johnson & Johnson, a global health-care company, suspended advertising on YouTube globally.
An AT&T spokeswoman was quoted by the publication as saying: “We are deeply concerned that our ads may have appeared alongside YouTube content promoting terrorism and hate.
“Until Google can ensure this won’t happen again, we are removing our ads from Google’s non-search platforms.”
Search occupies a significant share in Google’s advertising revenue that stood at $79.4bn last year.
Google’s network business, that caters to displaying ads on other sites, earned a revenue of $4.4bn in the fourth quarter, accounting for nearly 20% of the firm’s total ad income.
In an attempt to resolve the crisis, Google began implementing new tools and policies. However, many advertisers want to see more details on the new measures initiated by the company.
A Google representative said: “As announced, we’ve begun an extensive review of our advertising policies and have made a public commitment to put in place changes that give brands more control over where their ads appear.
“We’re also raising the bar for our ads policies to further safeguard our advertisers’ brands.”