(MB) Aluminium premiums worldwide were mostly unchanged in the week ended Tuesday March 12, but spot premiums in Japan moved higher amid tightened spot supply due to continued port congestion.More Q2 MJP deals concluded at $105 per tonne European Rotterdam premiums stable in quiet market Weak spot demand leaves US Midwest premium unchanged Uptrend in Brazilian import premiums continues MJP port congestion boosts spot premium The spot main Japanese ports (MJP) aluminium premium continued to move higher this past week due to tightness in the spot market after major ports in Japan reported vessel congestion. Fastmarkets assessed the spot premium for aluminium P1020, cif MJP, at $100-110 per tonne on March 12, up by $10-15 per tonne from $85-100 per tonne a week prior. A continued wide contango in London Metal Exchange forward aluminium price spreads and positive expectations about second quarter demand helped the bullish run of the MJP spot premium. The LME’s benchmark cash/three-month spread was in a $25-per-tonne contango on March 12. “Demand in the second quarter will be stronger than the first quarter“.