Facebook will buy fast-growing mobile-messaging startup WhatsApp for $19 billion in cash and stock, as the world's largest social network looks for ways to boost its popularity, especially among a younger crowd, according to the Associated Press.
Facebook released a statement on Wednesday saying it will pay $4 billion in cash and about $12 billion in stock in its single largest acquisition, the AP reported.
The social network will also grant an additional $3 billion worth of restricted stock units to WhatsApp's founders, including Koum, according to the AP.
The social media company's latest buy is much larger in comparison to the $1 billion it paid for photo-sharing app Instagram, according to the AP.
As part of the deal, WhatsApp co-founder and Chief Executive Jan Koum will join Facebook's board, the AP reported. Facebook promised to keep the WhatsApp brand and service, and pledged a $1 billion cash break-up fee were the deal to fall through.
The deal translates to roughly 9 percent of Facebook's market value and is bigger than any acquisition made by Google, Apple or Microsoft, the AP reported.
WhatsApp has more than 450 million monthly active users. In comparison, Twitter had 241 million users at the end of 2013, according to the AP.
Facebook CEO Mark Zuckerberg says WhatsApp is on path to reach a billion users, the AP reported. "The services that reach that milestone are all incredibly valuable," Zuckerberg said.
Shares in Facebook slid 5 percent to $64.70 after hours, from a close of $68.06 on the Nasdaq, the AP reported.
