Copper rose on Friday, adding to the previous day's gains after comments by the European Central Bank about its commitment to protect the euro, and as investors hope further stimulus measures from the Federal Reserve could be on the cards.
Three-month copper on the London Metal Exchange climbed to $7,519.50 a metric ton (1.1023 tons) at 05.23 a.m. EDT, up 0.7 percent from Thursday's close of $7,470 a metric ton.
The metal used in power and construction, which hit a one-month low of $7,344.25 a metric ton hit on Wednesday, was on track to close the month of July down more than 2 percent.
The euro steadied after rallying on ECB chief Mario Draghi's pledge to do "whatever it takes to preserve the euro", sending a strong signal that the bank could take steps to rein in soaring Spanish and Italian borrowing costs.
"There was a big relief rally after Draghi's comments calmed the market down by saying the ECB will do whatever it takes for the euro zone, and the market is reassured by that," said Nic Brown, head of commodity research at Natixis.
A weak dollar makes commodities priced in the U.S. unit cheaper for holders of other currencies.
Investors will keep a close eye on U.S. second quarter gross domestic product later in the session, for an indication of the pace of recovery in the world's largest economy.
The median of U.S. GDP forecasts from analysts polled by Reuters is for growth of 1.5 percent in the second quarter, down from the first-quarter's 1.9 percent expansion.
A weaker reading could pressure the U.S. Federal Reserve to adopt further monetary easing steps, a move which is seen supporting base metals and other risky assets.
"It is not just a case of looking at Q2, which is likely to disappoint relative to Q1, but you will also get revisions and it is entirely likely that they will portray the recent quarters in a very much more negative light than the market had previously understood," Brown said.
"So you could get a disappointment in the numbers, and the markets are looking for the Fed to announce further stimulus measures."
Investors worry that demand from top consumer China, which accounts for 40 percent of global copper demand, has been slow to pick-up so far this year, dragging prices 9 percent lower in the second quarter.
But China's refined copper consumption is forecast to rise by about 5 percent in the second half of 2012 from a year ago, a state-backed research firm said, led by higher demand from power cable makers as the government takes steps to boost the economy.
Still, the open interest in the LME copper contract has dropped to its lowest level in nearly five years, reflecting a lack of conviction about copper's near term price direction. The latest LME data shows open interest at 233,839 lots, the smallest volume since August 2007.
On aluminum, RBC Capital said in a note that price-induced shutdowns by aluminum producers such as Bosnia's Aluminij Mostar could erode a market surplus forecast for this year, potentially paving the way for a price recovery.
"The analyst community is still working on the numbers, but (such) closures could be enough to seriously erode the previously expected surplus," it said.
"Add that to the already tight physical market owing to load out queues at LME warehouses and you have a recipe for a decent short-covering rally," it said in a note.
Bosnia's top exporter, aluminum smelter Aluminij Mostar, will close 12.5 percent of its smelting capacity due to lower metal prices and higher power costs, and could cut more in September.
The roughly 45 million metric ton aluminum market is seen in a 500,0000 surplus this year, according to a Reuters poll earlier this month.
Benchmark aluminum rose to $1,887.75 a metric ton, from Thursday's close of $1,878.50.
Battery material lead climbed to $1,902.25 a metric ton from Thursday's close of $1,885 and zinc, used in galvanizing, rose to $1,831 from $1,815 on Thursday.
Stainless-steel ingredient nickel was at $15,961 from $15,890 and soldering metal tin climbed to $18,025 from Thursday's close of $17,750.