* Growing supply weighs on market sentiment
* Tin trade picks up on Indonesia ICDX exchange
* Euro zone economy stagnant in 3rd quarter
LONDON, Nov 14 (Reuters) - Copper ended little changed on Thursday, near a three-month low, pressured by uncertainty over the timing of a scale-back in U.S. monetary stimulus, growing supply and poor economic data from Europe.
Benchmark copper on the London Metal Exchange closed at $6,992 a tonne, up marginally from $6,980 on Wednesday, after hitting an intra-day low of $6,940, its lowest since Aug. 7.
"There have been a lot of Fed comments in the past few weeks that seem to suggest that tapering this year is not completely off the agenda, and there is also supply building in copper," Robin Bhar, an analyst at Societe Generale, said.
"Underlying fundamentals are certainly turning more negative for copper. I think the shorts are in the driving seat."
Data showing the euro zone economy stagnated in the third quarter also dimmed demand prospects for the industrial metal used in construction and wiring.
"Copper was already under pressure when it broke below a very important technical level. People began short-selling below $7,100. The weaker European data also weighed on sentiment," VTB Capital analyst Andrey Kryuchenkov said.
The supply of copper is expected to outstrip demand in the next few years.
In one recent development, for example, Rio Tinto is set to submit a mine plan to U.S. authorities this week for its $6 billion Resolution project in Arizona, which could become the largest copper producer in North America.
Benchmark tin closed at $23,000 from $22,825 on Wednesday.
New regulations in top tin exporter Indonesia, which force local producers to trade on a domestic exchange before exporting, have curtailed availability of the metal.
"Supply has definitely tightened up, even for low-purity tin, in the past month. A lot of people are looking for alternative sources of supply," a physical trader in Singapore said.
Stocks of tin in LME-registered warehouses have dropped to their lowest in about a year.
Trading volumes of Indonesia's tin contracts have picked up in the past two days, although they remain at low levels of around 140 lots, equivalent to 700 tonnes that will be available for export.
Benchmark LME aluminium ended at $1,791 from $1,795 on Wednesday, while lead was at $2,095.50 from $2,098 and zinc at $1,886 from $1,886. Nickel, untraded at the close, was bid at $13,650 from $13,675.
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
Three month LME tin