* Gold up on safe-haven bid as Libya ceasefire questioned
* Investors nervous about violence in Bahrain, Syria
* Goldman expects gold to hit record $1,480 in 3 months
* Coming up: U.S. existing home sales on Monday (Updates prices, adds comment, detail)
By Frank Tang
NEW YORK, March 18 (Reuters) - Gold rose for a third straight day on Friday after a unilateral ceasefire declared by Libyan leader Muammar Gaddafi failed to calm investor nerves as political tensions remained elevated across the Arab world.
Bullion also benefited from a weaker dollar as traders braced for more official action after the G7 countries coordinated to intervene on the yen, and as fresh political unrest was reported in Yemen, Syria and Bahrain.
"It's the concern about what would happen in Libya. Will Gaddafi really stick up to the ceasefire? That's probably the only reason why gold's being bid up at all," said Dennis Gartman, author of the Gartman Letter, an investment newsletter.
Recently weaker volume suggested, however, gold could lack the conviction to rise further, and Friday's gains were largely driven by the drop in the dollar, Gartman said.
Spot gold <XAU=> rose 1.1 percent to $1,418.10 an ounce by 2:58 p.m. EDT (1858 GMT). The U.S. April contract <GCJ1> settled up $11.9 at $1,416.10.
Total COMEX trade was about 15 percent lower than its 30-day average. Lower-than-usual turnover during gold's gains prompted some traders to doubt the metal had momentum to rise further.
In Asian trade, the market largely ignored news that China's central bank raised lenders' required reserves by 50 basis points, a move viewed by some as a confirmation of gold's inflation-hedge appeal. [
]The metal ended the week flat after dropping 1 percent last week, as Japan's earthquake, tsunami and nuclear crisis sent some investors to the sidelines with global equity and commodity markets still reeling from heavy losses.
"People are anxious about the commodities complex at the moment. With what happened in Japan coupled with concerns of high oil prices, investors are worried that the economy and demand for commodities would suffer," said Mark Luschini, chief investment strategist at Janney Montgomery Scott.
Noncommercial net long positions, or bullish bets, fell about 9 percent in the week to March 15 as prices weakened, according to the Commitments of Traders report by the U.S. Commodity Futures Trading Commission. [
]Spot silver <XAG=> rose 2.5 percent to $35.02 an ounce, with volume about one-third lower than its 30-day norm.
PUT-CALL SKEW NARROWS
On the options front, put buying was favored over calls, as investors combined a strategy to buy puts and sell calls to protect against downside risk. The implied volatility gap between puts and calls, however, has narrowed.
(Graphic on put-call skew: http://r.reuters.com/rud68r )
"With everything going on in Libya and Japan, nobody wants to go home short on Fridays," COMEX gold options floor trader Dominick Cognata said.
"The gold market has been very news-sensitive. As soon as any bit of new information comes out, we have a spike one way or another."
Gold is underpinned by renewed economic worries as Japan's battle against its nuclear emergency has shaken confidence in global financial markets this week. [
]Violence in North Africa and the Middle East also boosted gold. In Libya, western warplanes prepared to attack Gaddafi's forces, while political unrest lingered in Bahrain, and protesters were killed in Syria and Yemen.
Currency fluctuations benefited gold, as the dollar fell broadly but rose 3 percent against the yen after the Group of Seven launched its first coordinated intervention in currency markets since 2000. [
]Market sentiment improved after U.S. investment bank Goldman Sachs Group Inc <GS.N> forecast gold rallying to a record $1,480 an ounce in three months on declining U.S. real interest rates. [
]Platinum rebounded after the market fretted about a loss of demand due to car plant closures in Japan earlier this week.
Major automakers, led by world No. 1 Toyota Motor Corp <7203.T>, remain shut and may stay that way for some time as they struggle to restart production amid a shortage of parts and workers.
Platinum <XPT=> gained 1.1 percent to $1,716.49 an ounce and palladium <XPD=> climbed 3.3 percent to $727.97 an ounce. Prices at 2:58 p.m. EST (1858 GMT)
LAST/ NET PCT YTD
CLOSE CHG CHG CHG US gold <GCJ1> 1416.10 11.90 0.8% -0.4% US silver <SIK1> 35.058 0.800 0.0% 13.3% US platinum <PLJ1> 1723.40 16.50 1.0% -3.1% US palladium <PAM1> 731.20 14.40 2.0% -9.0% Gold <XAU=> 1418.10 15.70 1.1% -0.1% Silver <XAG=> 35.02 0.84 2.5% 13.5% Platinum <XPT=> 1716.49 19.00 1.1% -2.9% Palladium <XPD=> 727.97 23.47 3.3% -8.9% Gold Fix <XAUFIX=> 1420.00 4.50 0.3% 0.7% Silver Fix <XAGFIX=> 35.15 68.00 2.0% 14.8% Platinum Fix <XPTFIX=> 1720.00 1.00 0.1% -0.6% Palladium Fix <XPDFIX=> 727.00 5.00 0.7% -8.1% (Additional reporting by Rebekah Curtis in London; Editing by Dale Hudson)