Pope Francis has chosen Brazil's Cardinal Claudio Hummes to serve as relator general of October's Synod of Bishops on the Amazon.

The nomination of the 84-year-old retired Archbishop of Sao Paulo was announced at the Vatican on May 4. The relator is responsible for providing a comprehensive outline of the synod's theme at the beginning of the meeting and for summarising the speeches of synod members before work begins on concrete proposals for the pope.

Scheduled for Oct. 6-27, the synod will focus on "Amazonia: New paths for the church and for an integral ecology."