Barcelona - WhatsApp, which Facebook agreed to buy last week, was “worth more than $19 billion (R207bn), Facebook chief executive Mark Zuckerberg said on Monday.

The mobile-messaging startup was “a great fit for us”, Zuckerberg said at the Mobile World Congress in Barcelona. “Already almost half-a-billion people love using WhatsApp for messaging and it’s the most engaging app we’ve ever seen exist on mobile by far.”

The cash-and-stock acquisition would be the biggest by Facebook, the largest social network, and the most expensive for an internet firm in more than a decade.

The deal gives WhatsApp roughly the same valuation as Gap and more than half the market value of Twitter.

Zuckerberg, who also bought photo-sharing service Instagram for about $700 million in 2012, has been adding applications such as messaging and news to court smartphone and tablet users.

He said the WhatsApp deal would help Facebook play a more important role in getting more people connected.

WhatsApp lets users send messages through its service on mobile devices based on different operating systems including Apple’s iOS, Google’s Android, Microsoft’s Windows Phone and BlackBerry’s proprietary software.

Unlike traditional text messages, for which cellular operators charge consumers, WhatsApp is free for the first year, and costs 99c a year after that. It also competes with Tencent Holdings’ WeChat in China, KakaoTalk in Korea and Line in Japan, as well as Facebook’s own Facebook Messenger.

While declining to comment when asked whether he would make a bid for Snapchat, Zuckerberg said after a large deal such as WhatsApp, “you’re probably done for a while”.

While WhatsApp had low revenues, it would be worth more because of its strategic value, huge business potential to double its users and its fit with Facebook.

Zuckerberg also said he was seeking three to five phone companies as partners in an effort to connect billions of people to the internet. – Bloomberg