* Copper set for negative end to week
* Worries over supply from Chile, Indonesia limit losses
* Nickel prices ease, but still bolstered by supply concerns (Recasts to show copper down, updates prices)
By James Regan
SYDNEY, Feb 17 (Reuters) - Late Asian trading on Friday saw a bout of profit taking pare back copper prices to just under $6,000 a tonne, setting the stage for the metal to finish the week in negative territory. By 0750 GMT, three-month copper on the London Metal Exchange had dropped 0.5 percent to $5,970 a tonne, after earlier climbing as far $6,038. The contract fell over 1 percent the session before and was on track for a loss of close to 2 percent for the week.
Concerns over major supply stoppages in Chile and Indonesia swept the metal to a 21-month high of $6,204 on Monday.
The positions of BHP Billiton and the striking union at its Escondida copper mine in Chile -- accounting for about 6 percent of world supply -- remain distant even as the two parties agreed this week to return to the table.
All work has also stopped at Freeport-McMoRan Inc's giant copper mine in Indonesia, where workers plan to demonstrate against the government's decision last month to halt exports of copper concentrate, according to a union.
"Copper is still finding support from the strike at BHP and from the Grasberg hold up," said a trader in Perth, declining to be identified as he was not authorised to speak with media.
The most-traded copper contract on the Shanghai Futures Exchange on Friday slipped 1.3 percent to 48,360 yuan ($7,042) a tonne.
Elsewhere, nickel slipped from a two-month high reached yesterday as some investors took profits, traders said.
They added that supply worries would also continue to bolster nickel prices.
The Philippines this week ordered the cancellation of 75 mineral production-sharing agreements as developing them would threaten water supplies. That came after the closure or suspension of 28 of the country's 41 mines.
Benchmark LME nickel was down 1 percent at $10,945 a tonne after rising 1.4 percent overnight to its strongest since Dec. 19. Roughly two-thirds of global nickel supply is used to make stainless steel.
LME aluminium was down 0.8 percent at $1,882 a tonne, while zinc was off 0.5 percent at $2,845.
In Shanghai, lead dropped over 2 percent, while nickel finished up 0.2 percent.
Three month LME copper
Most active ShFE copper
Three month LME aluminium
Most active ShFE aluminium
Three month LME zinc
Most active ShFE zinc
Three month LME lead
Most active ShFE lead
Three month LME nickel
Most active ShFE nickel
Three month LME tin
Most active ShFE tin ($1 = 6.8673 Chinese yuan renminbi) (Reporting by James Regan; Editing by Joseph Radford and Christian Schmollinger)