LINE and Telefonica have partnered to offer the messaging app exclusively on the operator’s Firefox OS-based devices in Spain and Latin America.

The messaging app will soon be preloaded on Firefox OS devices offered by Telefonica in Spain, Brazil, Mexico, Venezuela, Peru, Colombia and Uruguay. More markets will follow.

Telefonica will also roll out the LINE app to existing devices via Firefox OS updates. LINE is already available in the Firefox OS Marketplace globally.

Jeanie Han, CEO of LINE Euro-Americas Corp, said the partnership underscores the company’s “commitment to our expanding European and Latin American customer base”.

“LINE’s messaging app enables us to strengthen what we are already offering our customers and will open up even more collaborative opportunities in 2014,” added Francisco Montalvo, the director of Telefonica’s group devices unit.

LINE claims to have more than 330 million registered users with growing interest in Latin America. However, the company does not specify how many active users it has, unlike fellow messaging app WhatsApp which claims to have more than 430 million monthly active users.

Telefonica has rolled out Firefox OS devices in seven countries since July last year. Mobile operators Telenor, Deutsche Telekom and TIM have also launched devices using the HTML5-based OS.

There are an increasing number of partnerships between mobile operators and messaging app players, despite concern that the growth of OTT apps could eat into operator revenue.

Examples include WhatsApp working with Indian operator Tata Docomo to launch data packs to allow unlimited use of the app for prepaid customers. WhatsApp also partnered with VimpelCom across multiple markets.

In November last year, Singapore’s StarHub launched support for Tencent’s WeChat as part of a prepaid service plan, while China Unicom launched a WeChat SIM card.