Alumina exports fell 6.6% year-on-year in September as a result of a reduction in volumes sent to Europe and the Middle East.
Exports totalled 653,880 tonnes, compared with 700,577 tonnes in September 2012.
Revenues for the month stood at $153.50 million, down from $170.26 million a year ago.
Norway reduced its volumes to 136,078 tonnes, compared with 158,729 tonnes a year earlier.
Qatar acquired 99,098 tonnes reporting a slight decrease from 102,892 tonnes in September 2012.
By contrast, Canada increased its volumes to 248,781 tonnes in September 2013, from 168,740 tonnes in September last year.
In the January-September period of 2013, alumina exports totalled 5.16 million tonnes, down 5.6% on the year.