Technology giant Facebook has announced plans to integrate WhatsApp, Instagram and Messenger.

The merger is intended to create "the best messaging experiences" for the billions of users around the world who use the Facebook-owned apps.

The apps will remain distinct from each other, although the underlying messaging infrastucture would be unified, according to people familiar with the matter.

A spokesperson for Facebook said the merger would deliver a messaging platform that was fast, simple, reliable and private, though data experts have warned it could have an impact on people's privacy.

"We’re working on making more of our messaging products end-to-end encrypted and considering ways to make it easier to reach friends and family across networks," The spokesperson said.

12 useful WhatsApp features you didn’t know existed Show all 12 1 /12 12 useful WhatsApp features you didn’t know existed 12 useful WhatsApp features you didn’t know existed Unsend messages You can unsend a message by tapping and holding it, hitting the Delete symbol and selecting Delete for Everyone. The feature works for all types of messages, but only if they were sent less than seven minutes ago. 12 useful WhatsApp features you didn’t know existed Dodge the blue ticks WhatsApp’s blue ticks show when sent messages have been read, but you can disable them buy going to Settings > Account > Privacy > Read Receipts. However, bear in mind that, by doing so, you’ll lose the ability to see when your own sent messages have been read. Another, more fiddly way of reading your messages without triggering the blue ticks, is enabling Aeroplane Mode before opening your messages - just remember to close the app before switching Aeroplane Mode off again. 12 useful WhatsApp features you didn’t know existed Hide your 'last seen' time Prevent your friends from finding out when you were last online by hiding your last seen time. Go to Settings > Account > Privacy > Last Seen. As is the case with disabling read receipts, hiding your ‘last seen’ time will also stop you from seeing anybody else’s. 12 useful WhatsApp features you didn’t know existed Limit data usage You can control how much data you munch through on WhatsApp by limiting the types of media you automatically download on a mobile connection. Go to Settings > Data Usage and choose the best option for you. 12 useful WhatsApp features you didn’t know existed Customise notifications If you’re expecting an important WhatsApp message from someone, set a custom notification for them by opening the chat, tapping their name at the top and hitting Custom Notifications. 12 useful WhatsApp features you didn’t know existed Format your messages To jazz up any of your messages, simply highlight it by tapping and holding it, hit the More Options key on the pop-up menu and tap the formatting option you want - bold, italic, strikethrough or monospace. 12 useful WhatsApp features you didn’t know existed Type hands-free You can get Siri or Google Assistant to type your WhatsApp messages out for you by saying either “Hey Siri” or “Okay Google”, followed by the name of the person you want to message and the actual contents of the message. 12 useful WhatsApp features you didn’t know existed Mark chats as unread When you’ve read a message but can’t reply to it straight away, you can set a visual reminder by marking it as unread. On Android, long-press the conversation, and on iOS, swipe from left to right on a chat. 12 useful WhatsApp features you didn’t know existed Email entire conversations You almost certainly won’t do this on a regular basis, but it’s a handy option to have. You can export entire conversations - complete with emoji and media attachments - by hitting More inside a chat a selecting Email Chat. 12 useful WhatsApp features you didn’t know existed Mass-message contacts You can send the same message to lots of your contacts without lumping them all into one group, much like the BCC option on email, by hitting the New Broadcast option on the app’s main menu. 12 useful WhatsApp features you didn’t know existed Pin conversations You pin up to three contacts and groups to the top of your WhatsApp conversation list by tapping and holding a chat, then hitting the pin icon. 12 useful WhatsApp features you didn’t know existed Make things easier to find You can easily mark key messages with a star, allowing you to find them easily when you need to. Just tap and hold a message and hit the star icon to save it, and return to it later by selecting Starred Messages in WhatsApp’s main menu.

No official details have been released, but the merger is expected to take place by early next year, The New York Times reported.

The messaging app merger is a backtrack on Facebook CEO Mark Zuckerberg's original stance that both Instagram and WhatsApp would operate autonomously from the social network.

Facebook acquired photo-sharing platform Instagram for approximately $1bn (£761m) in 2012, before taking over the messaging app WhatsApp in 2014 for an estimated $19.3bn.

Both apps have since experienced rapid growth – Instagram has around 1 billion monthly active users and WhatsApp has 1.5 billion users – though all original founders of the apps have since left Facebook.

WhatsApp employees were reportedly upset by plans to merge the app's messaging services with the other apps, making their views known during a contentious staff meeting in December.

One of the main points of contention with integrating the apps could be related to data privacy. Currently WhatsApp users are not required to provide their name or any other identifying information beyond their phone number to use the messaging app.

Merging with Facebook Messenger and Instagram could force WhatsApp users to reveal information about themselves that they would prefer to keep private.

Data privacy expert Tim Mackey, who works at the software firm Synopsys, told The Independent that Facebook should take considerable care in how the integration ws handled given the firm's "spotty history" with user privacy.

"Merging personal information and privacy configurations from three significant applications won’t be trivial," he said. "Facebook development teams would do well to look at this precedent and prioritise user privacy.

"With the integration project currently expected to take a year to complete, and with end-to-end encryption as part of the plan, we should expect the Facebook engineering teams to focus attention on uniform data security both in their platform and in the apps themselves.”