The most-traded April copper contract on the Shanghai Futures Exchange gained 0.5 percent to 60,620 yuan ($9,600) a tonne. "Copper is a bellwether for global growth and any sort of negative macro themes will mean copper will be pressured," said Natalie Robertson, a commodity strategist at ANZ Investment Bank in Melbourne.
"The market's still very much watching what's happening in Greece and now Portugal is starting to come back into the picture. That's quite a worry."