DHAKA: Facebook, the world`s biggest social-networking company, says it is buying the mobile messaging service WhatsApp in a deal worth $19bn.

The purchase, announced on Wednesday, will leave WhatsApp with its own independent board, reports Al-jazeera.

WhatsApp is a cross-platform mobile app which allows users to exchange messages without having to pay telecom charges.

It is Facebook`s biggest acquisition and comes less than two years after Mark Zuckerberg`s firm raised $16bn in the richest technology-sector public stock offering.

The purchase includes $12bn in Facebook shares and $4bn cash.

It calls for an additional $3bn in restricted stock units to be granted to WhatsApp founders and employees that will vest over four years.

"The acquisition supports Facebook and WhatsApp`s shared mission to bring more connectivity and utility to the world by delivering core Internet services efficiently and affordably," Facebook said in a statement.

The WhasApp deal translates to roughly nine percent of Facebook`s market value and is bigger than any acquisition made by Google, Apple or Microsoft.

Google`s biggest deal, Motorola Mobility, stood at $12.5bn, while Microsoft`s largest was Skype - which allows users to make voice and video calls over the internet - at $8.5bn. Apple, meanwhile, has not done a deal above $1bn.

Separate service

Facebook, which has more than 1.2 billion members, said it will keep WhatsApp as a separate service, just as it did with Instagram, which it bought for about $715.3m.

WhatsApp has more than 450 million monthly active users. In comparison, Twitter had 241 million users at the end of 2013.

"WhatsApp is on a path to connect one billion people. The services that reach that milestone are all incredibly valuable," Zuckerberg, Facebook`s founder and chief executive, said.

"I`ve known [WhatsApp founder] Jan [Koum] for a long time and I`m excited to partner with him and his team to make the world more open and connected."

Koum, who joins Facebook`s board under the deal, said "WhatsApp`s extremely high user engagement and rapid growth are driven by the simple, powerful and instantaneous messaging capabilities we provide."

In a blog post, Koum said, "Almost five years ago we started WhatsApp with a simple mission: building a cool product used globally by everybody. Nothing else mattered to us."

The tie-up gives WhatsApp "the flexibility to grow and expand, while giving me, [co-founder] Brian [Acton], and the rest of our team more time to focus on building a communications service that`s as fast, affordable and personal as possible," Koum said.

Facebook reportedly sought to acquire another messaging firm, Snapchat, for $3bn last year.

BDST:  HRS, FEB, 2014