U.S. copper futures strengthened to near 15-month highs Thursday morning, driven by extended losses in the dollar,supply threats in Chile, and pre-holiday momentum buying. For detailed report on global copper markets, click on [MET/L]

* Benchmark copper for March delivery HGH0 firmed 4.45 cents to $3.2480 a lb by 9:09 a.m. EST (1409 GMT) on the New York Mercantile Exchange's COMEX division.

* Range from $3.1920 to $3.25, the contract's loftiest level since Dec.4, and near a 15-month peak at $3.2750.

* Weekly buy-signal triggered at $3.22 a lb drove early gains. Momentum could carry market up to challenge of yearly high at $3.2750 - Larry Young, senior trader at Infinity Futures Inc. in Chicago.

* Weaker dollar driving much of the rally in treacherously thin market conditions - MF Global analyst Edward Meir. * COMEX estimated futures volume at 5,002 lots by 9 a.m.

* Some New York energy and commodity will close early on Thursday, Dec. 24, and all will be closed on Friday for Christmas Day. Business will resume on Monday.

* The dollar trimmed losses against the euro on Thursday after data showed U.S. durable goods orders rose in November, while initial jobless claims fell last week. [ID:nN24182625] [ID:nN23158877]

* Weaker dollar makes commodities priced in the American currency more attractive to non-U.S. investors. [USD/]

* Copper underpinned by potential supply threat at one of the world's largest copper mines, Codelco's Chuquicamata, if union workers reject final wage offer.

* Codelco said it will have enough copper stocks to honor contracts early next year if union workers strike. [ID:nN23160262]

* London Metal Exchange copper warehouse stocks added another 2,025 tonnes to eight-month peak at 484,800 tonnes on Thursday. <0#LME-STOCKS>

* COMEX copper stocks rose by 827 short tons to 98,021 short tons as of Wednesday.

* Japanese and Chinese copper smelters agreed to a 38 percent cut in 2010 treatment charges with Freeport-McMoRan Copper & Gold Inc (FCX.N). [ID:nSGE5BN025]

* LME three-month copper MCU3 last traded at $7,080 a tonne, up $80 from Wednesday's close.

(Reporting by Chris Kelly; Editing by John Picinich)