NEW YORK/LONDON—The price of copper in New York and London ended up on Friday, with a weaker dollar and strong underlying supply/demand fundamentals keeping the red metal's bullish momentum firmly in place, traders and analysts said.

At the New York Mercantile Exchange's COMEX division, copper for May delivery settled up 2.05 cents at $3.9445 a lb, after dealing between $3.9020 and $3.9765.

On Thursday, May copper hit a contract high at $4.0390. It was the highest level for a second-month contract on a spot continuation basis since May 2006.

"The fundamental news is definitely bullish and the technicals are as well," said Zachary Oxman, senior trader with Wisdom Financial in Newport Beach, California. "The [$4.00] resistance level is pretty strong up there. It's part technical, but I think it's more mental than technical at this point.

"I think if we can get through that level people are going to start begrudgingly getting back into the market," he said.

Copper for three-month delivery on the London Metal Exchange was untraded at the curb but was quoted at $8,645/8,650 a metric ton versus $8,620 on Thursday, when it tried and failed to break through its record from March 6, at $8,820 a metric ton.

"It's holding pretty well. The Chinese data was bullish and the dollar weakened, though trading volumes haven't been very big," said David Thurtell, metals analyst at BNP Paribas.

China, the world's biggest copper buyer, hiked imports of unwrought copper and semi-finished products by six percent in March to 240,634 metric tons. The increase reflects stronger demand after snowstorms and holidays reduced consumption in February.

“[The] report from China shows that despite very high prices, demand is staying very robust. This has driven the market higher," said Eugen Weinberg, metals analyst at Commerzbank.

"On one hand we have very strong demand in China and on the other interruptions in production in Latin America. This gives a rather bullish picture," Weinberg said.

Copper continued to find support from ongoing weakness in the dollar, which fell broadly as a disappointing earnings report from US industry giant General Electric Co. and a worse-than-expected US consumer confidence report added to concerns about the country's economic outlook.

A weaker greenback makes metals, priced in dollars, cheaper for investors buying in other currencies, thus often increasing appetite. The euro last traded at $1.5812.

BNP's Turtell commented that the downbeat US consumer confidence data should be bearish for base metals.

"These days anything that leads to dollar weakness gives copper and commodities a bit of a lift," he said. "But the reality is that things are weakening in the world's biggest economy and that should be poor for base metals."

The market was waiting to hear if the Group of Seven finance ministers and central bankers—meeting in Washington—say anything later in the day about the dollar, which if it weakens further could boost metals.

Investors will also scrutinize any comments on the banking crisis that has weighed on real economic activity and equities markets.

Up 30 percent this year, copper has increasingly been labeled a "safe haven," driven largely by investor money flows into the strongly performing commodity sector.

Looking ahead, analysts remain bullish about the red metal's price prospects this year given the bullish backdrop of tight supply.

Inventories in LME warehouses have nearly halved year-to-date—down 950 on Friday to 115,150 metric tons, enough for about two days' global consumption.

"We see another big [copper] deficit in Q2, inventories returning to all-time lows and prices testing all-time highs again," Barclays Capital said in a research note. "The metal most at risk from a slowing in future production due to tight energy markets is aluminum."

Some analysts expect to see an aluminum market deficit this year, which together with strong demand from consumers and investors could send prices higher, possibly toward the record high of $3,310 a metric ton seen in May 2006.

Next week, US macroeconomic data and company earnings reports may give direction to the dollar and thus metals.

Aluminum closed at $3,095 a metric ton, up from $3,082 at the close on Thursday. Nickel was untraded at the curb but was quoted at $28,500/28,600 versus $29,000. Zinc closed at $2,310, down from $2,340, and lead at $2,967 versus $2,910.

Tin, which on Thursday briefly touched a contract high of $20,990 was untraded at the curb but changed hands at $20,700/20,800 versus $20,700/20,750.

Bolivian mining firm Comibol said a strike had paralyzed the country's biggest tin mine, Huanuni, for 10 days, causing losses of nearly $500,000 per day.