German giants Volkswagen, Puma and Adidas on Tuesday joined a growing advertiser boycott over hate speech against Facebook, following major consumer companies like Levi's and Coca-Cola.

Some 200 brands have now paused advertising with the social media giant as part of the #StopHateForProfit campaign launched by social justice activists.

The unprecedented move has already wiped billions off Facebook's market value.

Car giant Volkswagen, which also owns the Audi, Porsche and Skoda brands, said it was suspending the group's ads on Facebook.

"Hate speech, discriminating comments and posts containing dangerous false information must not be published uncommented and must have consequences," the group said.

Sportsgear maker Puma said it was joining the #StopHateForProfit campaign "throughout July".

Puma "is part of an overall effort to create positive change and improvement in Facebook's platform by demanding the removal of inaccurate, hostile and harmful conversation," a spokeswoman said.

A spokesman for Puma's rival Adidas said the company would "develop criteria to develop and maintain a cosmopolitan and safe environment that will apply to ourselves and our partners" during a Facebook ad pause also encompassing US subsidiary Reebok.

Adidas is itself no stranger to controversy
Adidas is itself no stranger to controversy AFP / Odd ANDERSEN

"Racism, discrimination and hateful comments should have no place either in our company or in our society," he added.

The movement against online hate speech has picked up steam following George Floyd's death on May 25 at the hands of a white policeman in Minneapolis.

On Friday, Facebook had said it would ban a "wider category of hateful content" in ads and add tags to posts that are "newsworthy" but violate platform rules -- following the lead of Twitter, which has used such labels on tweets from US President Donald Trump.

But experts have highlighted the social network's massive advertiser base of small- and medium-sized companies chasing over 2.6 billion worldwide users, potentially limiting the impact of big-name boycotts.

Adidas has itself been in the sights of the global anti-discrimination movement.

Earlier this month, the three-stripe brand rejected claims by employees that it was not doing enough to combat racism, after its human resources chief Karen Parkin last year described such complaints as "noise" only discussed in the US.

Parkin announced her resignation on Tuesday after 23 years at Adidas.

"It has become clear to me that to unify the organisation it would be better for me to retire and pave the way for change," she said in a statement.