LME aluminum may open higher as backwardation spread on cash to 3-month contract increasing ahead of February cash contract's expiry next Wednesday, says trader at Japanese house. LME 3-month last at $2,836/ton, +$16 on London PM kerb; cash contract at $2,915/ton, difference of $79, up from $55 Tuesday. Adds, short players will likely cover positions, roll contracts ahead of expiry date, pushing up aluminum prices, making the spread "much bigger." Notes martial law in Guinea not having large impact on market, as most movement coming from funds trading spreads.