Technicals,Peru strike lift US copper to 4-wk high

NEW YORK, June 18 (Reuters) - U.S. copper futures rallied 2.7 percent, or 9.80 cents a lb, on Wednesday as chart-based buying boosted values to their highest level in four weeks, while escalating strike action in South America provided additional support, analysts said.

NOTE: For detailed report, click on [MET/L].

* Copper for July delivery HGN8 settled 9.80 cents firmer at $3.7475 a lb on the the New York Mercantile Exchange's COMEX division, its loftiest level on a closing basis since May 20.

* The session range ran from $3.6415 to $3.7580.

* By 1 p.m. EDT (1700 GMT), estimated volumes hit 24,412 lots. Final volumes on Tuesday totaled 17,718 lots.

* Open interest increased by 233 lots to stand at 102,488 open contracts as of June 17.

* Copper rally driven by stronger technical backdrop, with buy signal at $3.6880 providing early momentum through the market's previous resistance at $3.70 - Larry Young, senior trader at Infinity Futures Inc. in Chicago.

* Taking out Monday's high at $3.7050 triggered additional buy-stop orders - Sterling Smith, vice president with FuturesOne in Chicago.

* Next significant resistance eyed at the May 16-19 double-top formation at around $3.86 - Scott Meyers, senior trading analyst with Pioneer Futures in New York.

* Copper underpinned by escalating strike action in Peru.

* Workers at Southern Copper's (PCU.N)(SPC.LM) Cuajone mine extended a strike, which began on Tuesday, indefinitely.

* The strike action was "greatly affecting" output at the mine, which produced 148,936 tonnes of the red metal last year. [ID:nN18257223]

* This followed a labor walkout at Peru's third-largest copper pit, Cerro Verde (CVE.LM), which was now in its eighth day. [ID:nN18467038]

* Inventory data showed London Metal Exchange (LME) copper warehouse stock levels grow by 350 tonnes to 123,900 tonnes on Wednesday.

* COMEX copper stocks were unchanged at 11,040 short tons on Tuesday.

* LME copper for three-months delivery MCU3 ended up $152 at $8,240 a tonne from Tuesday's closing level. (Reporting by Chris Kelly; Editing by Christian Wiessner)