NEW YORK ( TheStreet) -- Broader market optimism stemming from incremental developments in Greece helped copper and other commodities edge higher Tuesday.

Three-month copper was rising 0.6% to $9,020 per ton on the London Metal Exchange, while July futures were last gaining 4 cents to $4.09 per pound, or $9018.74 per ton, on the Comex in New York.

"We've been trading sideways as financial news has been mixed," said DTN commodities analyst Darin Newsom. "There's a lot of technical price resistance."

Newsom noted that in order to break out of the sideways trend, September and July futures would have to break above $4.15 per pound. "Copper needs signs of economic growth to post a solid rally, but right now we're not seeing that domestically or globally," he added.
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Copper mining companies were up on a stronger physical copper market with both Southern Copper ( SCCO) and Freeport-McMoRan Copper & Gold ( FCX) up more than 2%.

-- Written by Chao Deng in New York.

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