WhatsApp, which has about 1.5 billion users, has been trying to find ways to stop misuse of the app, following global concerns that the platform was being used to spread fake news, manipulated photos, videos without context and audio hoaxes, with no way to monitor their origin or full reach.

The messaging service said in January it would limit the number of times a user could forward a message to five in a bid to fight "misinformation and rumors."

Concerns about Facebook's handling of personal information have grown since the world's largest social network admitted in March that data of millions of users was wrongly harvested by political consultancy Cambridge Analytica.

In a blog post https://blog.whatsapp.com/10000661/New-Privacy-Settings-for-Groups, WhatsApp said a user inviting another to a group will be prompted to send a private invite through an individual chat, giving the recipient the choice of joining the group. The request will expire in three days.

Facebook, when asked about the default setting in the privacy option, said the default is "everyone".

The setting will be rolled out on Wednesday for some users and be available worldwide in the coming weeks.

WhatsApp, seen as a key tool for communications and commerce in many countries, was acquired by Facebook in 2014 for $19 billion.

(Reporting by Vibhuti Sharma in Bengaluru; additional reporting by Manas Mishra; Editing by Shinjini Ganguli and Lisa Shumaker)

By Vibhuti Sharma