The Telegraph reports:
The Swiss trading group had a barter agreement with the Iranian Aluminium Company (Iralco), under which Glencore provided alumina – used to make aluminium – in return for a smaller amount of the metal, sources told Reuters.
Iralco itself had a contract to supply aluminium to Iran Centrifuge Technology Co (TESA), a subsidiary of Iran’s Atomic Energy Organisation. That body leads its nuclear programme and has been subject to UN sanctions since 2006.
I have more on this over here.
Not an uncommon type of deal in the metals game. And alumina is not subject to nuclear stylee sanctions either. Very high purity aluminium tubes are, yes. But not alumina.