* U.S. consumer prices data underpins gold's gains
* Anti-government protests in Arab world in focus
* Tensions flare in Libya, Suez as unrest spreads
* Silver at 31-yr high; gold ratio at near 5-year low (Recasts, updates prices, adds comments, graphic; new byline and dateline, previously LONDON)
By Frank Tang
NEW YORK, Feb 17 (Reuters) - Gold prices rose on Thursday for a fourth day, their longest winning streak since September, as U.S. consumer price data stoked growing worries over inflation, adding fuel to safe-haven buying due to flaring Middle East tensions.
Bullion's gains sparked strong investment buying in silver, which rallied to a 31-year high, further widening silver's gains over gold and sending the gold-silver ratio to a near five-year low.
Gold buying was underpinned after data showed U.S. core consumer prices rose 0.2 percent in January, the fastest pace in more than a year, indicating a long period of slowing inflation had run its course. [
] Earlier this week, strong Chinese core inflation had also boosted gold."The CPI data showed there is a lot of inflation around now. Certainly, inflation and the concern about the Middle East in general are very supportive factors," said Bruce Dunn, vice president at bullion dealer Auramet.
Safe-haven buying increased as unrest spread across the Middle East and North Africa, after Bahrain on Thursday launched a swift military crackdown on anti-government protesters and clashes were reported in Libya and Yemen. [
]Gold was set for its strongest weekly performance since the start of the year, recovering from January, when it notched the biggest monthly decline in six months, as investor appetite was rekindled by rising political tensions, which also boosted other safe-haven investments like the Swiss franc <CHF=> and U.S. Treasuries <US10YT=RR>.
Spot gold <XAU=> rose to a five-week high at $1,384.30 an ounce and was up 0.7 percent at $1,383.53 an ounce by 12:38 p.m. EST (1738 GMT). U.S. gold futures for April delivery <GCJ1> rose $9.10 to $1,384.20.
Silver <XAG=> hit a session high of $31.38 an ounce and was up 2.4 percent at $31.37 an ounce in afternoon trading.
The gold-silver ratio -- the number of silver ounces needed to buy an ounce of gold -- fell to a low of 44, a key area near its lowest level in five years, as silver has outperformed gold. (Graphic: http://link.reuters.com/bec28r)
Year to date, silver was nearly 2 percent higher, swinging to positive territory with Thursday's rally, while gold was still 3 percent lower.
The prospect of rising inflation, not only in areas currently affected by the phenomenon such as China and India, but also in the United States and Europe, has become an oft-cited reason to hold gold in recent weeks.
"The mood of the market is that an inflation story, a war story, an Egypt story, a Bahrain story will all be bullish for gold, because the market is looking for those at the moment," said ANZ Bank analyst Peter Hillyard.
Gold and silver also benefit from a broad decline of the dollar versus a currency basket <.DXY> after data showed U.S. new unemployment benefit claims climbed faster than forecast last week. [
]UNREST SPREADS IN ARAB WORLD
Analysts said the metal could potentially rise further on safe-haven demand as unrest spread across the Middle East after protests earlier in the year unseated leaders in Tunisia and Egypt. [
] [ ]In the physical market, the World Gold Council said overall demand for gold is likely to remain firm this year, driven by buying from India and China, as it released a report showing consumption of the precious metal rose to a 10-year high in 2010. [
](BREAKINGVIEW: Gold bears may be overlooking Asia's gold bugs [
])Palladium <XPD=> eased a touch to $837.72, and platinum <XPT=> rose 0.6 percent to $1,838.24. (Additional reporting by Jan Harvey and Amanda Cooper in London; Editing by Walter Bagley) Prices at 12:51 p.m. EST (1751 GMT)
LAST NET PCT YTD
CHG CHG CHG US gold <GCJ1> 1383.70 8.60 0.6% -2.7% US silver <SIH1> 31.370 0.741 2.4% 1.4% US platinum <PLJ1> 1842.80 8.50 0.5% 3.6% US palladium <PAH1> 840.50 2.15 0.3% 4.6% Gold <XAU=> 1382.55 8.35 0.6% -2.6% Silver <XAG=> 31.34 0.71 2.3% 1.6% Platinum <XPT=> 1834.95 8.21 0.4% 3.8% Palladium <XPD=> 837.47 -0.50 -0.1% 4.7% Gold Fix <XAUFIX=> 1379.00 2.00 0.1% -2.2% Silver Fix <XAGFIX=> 30.61 -16.00 -0.5% -0.1% Platinum Fix <XPTFIX=> 1834.00 8.00 0.4% 6.0% Palladium Fix <XPDFIX=> 839.00 2.00 0.2% 6.1%