Major Rio Tinto has warned that iron-ore production for the full year would be at the lower-end of the original guidance of between 320-million and 335-million tonnes, despite the production in the September quarter increasing by 1% on the previous corresponding period and by 7% on the previous quarter. Rio on Tuesday reported that iron-ore production for the third quarter ended September reached 84.3-million tonnes, with 82.9-million tonnes of ore shipped, down 1% from the previous corresponding period, and up 4% on the second quarter.