Japan's March inventories of copper cathode totaled 50,490 metric tons, up 4.8% on month, according to preliminary data released Friday by the Ministry of Economy, Trade and Industry.
On year, copper stocks were up 5.9%.
According to the data, Japanese smelters produced 132,538 tons of copper cathode in March, up 6.3% from February, but up just 0.8% from a year earlier.
Copper shipments were mostly unchanged, rising 0.5% on month to 84,788 tons. On year, shipments were down 4.6%.
Friday, the three-month copper contract on the London Metal Exchange was trading $1 higher from the London Thursday afternoon kerb at $7,680 a metric ton after falling $201 overnight.