Updated, 7:25 p.m. He recently lost the pitcher Masahiro Tanaka to the New York Yankees, but Hiroshi Mikitani, the billionaire owner of the Japanese e-commerce giant Rakuten, may now have found some solace.
On Friday, Rakuten said it would buy Viber Media, which runs a popular app for calling and messaging, for $900 million.
The move by Rakuten would bolster Mr. Mikitani’s fast-growing empire, whose businesses already include the Rakuten online marketplace, a travel agency, credit cards and the baseball team Tohoku Rakuten Golden Eagles, which once had Mr. Tanaka on its roster.
The purchase of Viber Media could also heat up competition in the world of web messaging, where services such as WhatsApp of the United States, Line of South Korea and WeChat of China are fiercely vying for users.
Snapchat, whose app offers a variation on messaging that lets users send photo and video messages that disappear after they are viewed, turned down a multibillion-dollar takeover proposal from Facebook last year.
“With Viber, we’re going to link up messaging with e-commerce,” Mr. Mikitani said at a news conference in Tokyo. Rakuten’s users, for example, could use Viber instant messaging to communicate in real time with online retailers, he said.
The deal is expected to close next month, according to Rakuten. The company said it would finance the acquisition through bank borrowing.
Founded by Mr. Mikitani in 1997, Rakuten has expanded its footprint outside Japan with a series of prominent investments and acquisitions, including buying a stake in the Canadian e-book maker Kobo in 2011 and investing in the American virtual scrapbook site Pinterest in 2012.
The Rakuten site’s various services have about 200 million users worldwide, and Viber will bring Rakuten about 300 million more, according to the Tokyo-based company. Viber is one of the most popular apps for making phone calls and sending free messages on a smartphone, with the United States, Australia and Russia among its biggest markets.
Rakuten said on Friday that its net profit for the year through December doubled to 43.5 billion yen, or about $427 million, its sixth consecutive year of record earnings.
Viber, based in Cyprus, has recently become a rival to Skype, the audio, video and chat front-runner acquired by Microsoft in 2011. Late last year, Viber introduced an instant messaging and calling service for personal computers.
In the last two years, text, photo and video messaging apps have become one of the hottest areas in technology. Twitter Direct Messages, Google Plus, Kik, Tango, ooVoo and dozens of other apps are consistently among the most downloaded apps for consumers worldwide.
Many of these apps are used by hundreds of millions of people, too. WhatsApp, the mobile messaging platform, says it has more than 400 million monthly users. Skype reports close to 300 million users worldwide. And Facebook, which has more than 1.2 billion global users, is a major player in messaging, too. In many cases, people are turning to these messaging apps as free alternatives to pricey text messages, especially when conducting international conversations.
According to a Pew Research report released in December, 81 percent of American adults with a cellphone use the device for text messaging. And these messages are addictive. Pew said 67 percent of cellphone owners found themselves checking for messages and calls, even when their phone hadn’t made a vibrating or ringing sound.
There is also big money to be made on these messaging platforms. Line, the messaging app out of Korea, said last month that it now had more than 350 million registered users and the company generated $330 million in revenue last year from the sale of stickers and branded accounts in the app.
Mr. Mikitani suggested that Rakuten would be looking for other streams of revenue, too.
“In the future, e-commerce will become a more communication-based transaction,” Mr. Mikitani said. “Live interaction is going to be critical for all Internet services. Rakuten is at the start of a new era.”