NTT Docomo struck an agreement with LINE, one of the leading social messaging app providers, in a further sign of how mobile operators are looking to co-operate with Over-The-Top (OTT) players.

The two companies will develop original LINE applications for Docomo smartphone users, as well as look at ways to reduce the traffic load on the operator’s network.

LINE offers users free voice calls and messages to smartphone users over mobile networks as well as Wi-Fi.

The Docomo/LINE partnership will see an app developed specifically for the operator’s Raku-Raku range of simplified smartphones. This will be designed to prevent accidental purchases by users of additional LINE products and games by putting a limit on transaction amounts. The app will be launched by the end of 2013.

A second original app for the operator’s Android smartphones will feature a new call button that enables subscribers to directly access Docomo’s mobile network. Subscribers to its Xi LTE network can use this button to call other Docomo users for free at any time. This app will be launched by September this year.

Earlier this year LINE also struck another agreement designed to boost its distribution with Nokia, to bring its app to Nokia’s Asha line of handsets sold in Southeast Asia, Latin America, the Middle East and Africa.