COMMODITIES-Grain, oil losses end index winning streak

* TR CRB index retreats from 4-1/2-month high
* Gold up 1 pct, heads for biggest weekly gain since Jan.
* US crude dips back below 200-day moving average

By Jonathan Leff
NEW YORK, Aug 23 (Reuters) - Grains fell and oil pulled back
after a string of gains on Thursday, while copper and gold
gained in a session marked by mixed signals on the potential for
further central bank stimulus.
The Thomson Reuters-Jefferies CRB index fell for the
first time in eight sessions, retreating from a 4-1/2-month high
as U.S. stocks dropped and the euro rose to a seven-week
high. Downbeat economic data from China to Europe to the
United States weighed on riskier assets.
Bullion bucked the broader decline, however, rising nearly 1
percent to a four-month high and heading toward its biggest
weekly gain since January, bolstered by hopes for a new round of
U.S. monetary stimulus and news that Spain is negotiating
conditions for a possible aid package.
Wednesday's minutes from the U.S. Federal Reserve's August
meeting showed policymakers were ready to deliver more stimulus
"fairly soon" unless the economy improves considerably.
"This is the first insight we've gotten in the marketplace
to think that the Fed is committed to this new stimulus program,
and that's the catalyst you need to break out of the range,"
said Jeffrey Sherman, commodities portfolio manager at
DoubleLine Capital LP, with over $40 billion under management.
That followed talk that Spain was negotiating with the euro
zone over conditions for international aid, and by speculation
the European Central Bank was considering targeting yield levels
with its bond purchases.
Gold maintained gains even as other markets fell after James
Bullard, president of the St. Louis Federal Reserve and a
non-voting member of the Federal Open Market Committee,
suggested that the economy had improved since the last meeting,
comments that may have dimmed some expectations of further
easing.
In the United States, the data mix was weak. The number of
Americans filing new claims for jobless benefits rose
unexpectedly last week, manufacturing improved only slightly in
August and new single-family home sales rose in July but prices
fell.
While overall commodity trading volume was average, activity
was expected to slide into the weekend ahead of a UK holiday
next Monday. Only a handful of indicators are due on Friday,
including U.S. building permits and durable goods, as well as
the second release of Q2 GDP.

COPPER HOLDS UP
Three-month copper on the London Metal Exchange
ended up 1.05 percent at $7,684.50 a tonne, off an intraday peak
of $7,720, which was the highest since July 20.
Down 12 percent from a peak of $8,765 in February, copper
has broken out of a range of $7,300 to $7,600, which trapped it
for several weeks. It must challenge $7,800 to spark further
momentum, analyst Wiktor Bielski at VTB Capital said.
In China, data showed factory activity in August shrank at
the fastest pace in nine months as new export orders slumped and
inventories rose, a signal that a persistent slowdown in
economic growth has extended deeper into the third quarter.

OIL EYES STORMS
Brent October crude rose 10 cents to settle at
$115.01 a barrel, while U.S. crude fell 99 cents after failing
to maintain a break above the 200-day moving average on
Wednesday, the first time it had topped that level since May.
In addition to more upbeat sentiment, a flare up of tropical
storms in the Atlantic has added support to oil, with traders
hedging the risk of disruption to Gulf of Mexico output.
Tropical Storm Isaac weakened slightly near Puerto Rico and
the Virgin Islands, charting a course that could take it into
the eastern Gulf as a Category 1 hurricane around the weekend or
early next week. Tropical Storm Joyce also formed in the eastern
tropical Atlantic.

GRAINS PAUSE AFTER LATEST PUSH
In Chicago, November soybeans reached a contract high
of $17.44-3/4 per bushel in early trading, then dropped 0.7
percent to close at $17.15. December corn fell 20 cents or
2.4 percent to $8.14-3/4, falling short of a new record high.
The declines came despite dire production reports for corn
and soybeans from the annual Pro Farmer tour of Midwest crops.
Traders said the low yield and production data had already been
dialed into the market during the months-long rally.
"I think the market needs more bullish input now on a steady
basis to sustain gains. We would expect to chop around at these
high prices," said Shawn McCambridge, senior grain analyst for
Jefferies Bache. "Everybody got long and now we wait for fresh
news that might move it one way or another."

Prices at 3:57 p.m. EST (1957 GMT)
LAST/ NET PCT YTD
CLOSE CHG CHG CHG
US crude 96.10 -1.16 -1.2% -2.8%
Brent crude 114.72 -0.19 -0.2% 6.8%
Natural gas 2.802 -0.024 -0.8% -6.3%

US gold 1672.80 32.30 2.0% 6.8%
Gold 1670.10 16.21 1.0% 6.8%
US Copper 349.25 3.80 1.1% 1.6%

Dollar 81.379 -0.107 -0.1% 1.5%
CRB 307.240 -0.780 -0.3% 0.6%

US corn 814.25 -19.00 -2.3% 25.9%
US soybeans 1706.00 -9.00 -0.5% 42.3%
US wheat 904.25 -21.00 -2.3% 38.5%

US Coffee 161.85 -0.25 -0.2% -29.1%
US Cocoa 2385.00 5.00 0.2% 13.1%
US Sugar 19.59 -0.35 -1.8% -15.7%

US silver 30.456 0.900 3.0% 9.1%
US platinum 1553.90 28.40 1.9% 10.6%
US palladium 656.60 27.85 4.4% 0.1%