The companies will offer the Google chat service over Orange's network in the Middle East and Africa. It is already available in Senegal, Uganda and Kenya.
Africa's limited Internet infrastructure means that mobile phones have become the point of entry for high-speed Internet and other data services, including banking.
Emerging markets telecoms research firm Delta Partners expects non-voice revenue in Africa, including short messaging services, to hit $10 billion by 2014, from about $5 billion now.