A man is silhouetted against a video screen with an Facebook logo as he poses with an Samsung smartphone in this photo illustration taken in the central Bosnian town of Zenica in a file photo taken August 14, 2013. [Photo / Agencies]

Terms

Shares in Facebook slid 5 percent to $64.70 after hours, from a close of $68.06 on the Nasdaq.

Facebook said on Wednesday it will pay $4 billion in cash and about $12 billion in stock in its single largest acquisition, dwarfing the $1 billion it paid for photo-sharing app Instagram.

The price paid for Instagram, which with just 30 million users was already considered overvalued by many observers at the time.

Facebook promised to keep the WhatsApp brand and service, and pledged a $1 billion cash break-up fee if the deal falls through.

Facebook was advised by Allen & Co, while WhatsApp has enlisted Morgan Stanley for the deal.

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