Talmon Marco, the CEO of mobile messaging player Viber Media, denied the company is in talks to be acquired by an Asian company.

Israeli publication Calcalist reported that Viber had been approached about a possible acquisition valued at between $300 million and $400 million. The identity of the Asian bidder was not reported.

However, Marco told Reuters that he hadno idea what this is about” and said his company was not in talks regarding a sale.

Viber is run from Cyprus and has development centres in Israel and Belarus. It has around 200 million registered users in 193 countries with around 63 million believed to be based in Asia.

The company recently boosted its efforts to generate revenue by introducing functionality that enables users to make low-cost calls to any mobile or landline phone number. Viber Out brings Viber into more direct competition with Skype, which also supports voice calls to “traditional” phone numbers.

Viber’s first attempt to monetise its messaging app was the introduction of its Sticker Market, which it launched at the beginning of October.

Asia has seen the rise of a number of messaging apps, most notably WeChat in China, LINE in Japan and KakaoTalk in South Korea. All of these messaging services have user bases that stretch into the hundreds of millions.

Messaging apps have long been cited as eroding SMS revenue for operators, but as more of them move into voice, they could have an even greater impact.