* Investors watch Saudi Arabia
* Gold market remains tight, scrap sales seen
* Coming up: U.S. Feb retail sales due at 1330 GMT
(Adds comment/detail, updates prices)
By Pratima Desai
LONDON, March 11 (Reuters) - Gold slipped alongside oil on Friday but was supported after a major earthquake struck Japan and investors fretted about unrest in the Middle East.
The precious metal is on track for its biggest weekly decline since early January, down about $30 since hitting a lifetime high of $1,444.40 a troy ounce on Monday.
Spot gold <XAU=> was bid at $1,407.80 an ounce at 1145 GMT from $1,412.59 at the close on Thursday.
Investors protect their portfolios by buying gold when they expect rising price pressures, often fuelled by energy costs.
However, U.S. crude futures <CLc1> fell back below $100 a barrel, helping to ease fears of higher inflation, down about $4 from session highs. [
]The biggest earthquake to hit Japan since records began 140 years ago struck the northeast coast, triggering a 10-metre tsunami that swept away everything in its path, including houses, ships, cars and farm buildings. [
]"Gold is trading off oil, but Japan's earthquake and tension in the Middle East is helping," said Andrey Kryuchenkov, an analyst at VTB Capital. "Markets are nervous also with a planned 'day of rage' in Saudi Arabia."
Investors are watching to see what happens in Saudi Arabia, where a planned day of demonstrations will test whether activists calling for political reform will succeed in taking their protests to the streets. [
] [ ]Also on the radar was Libya, where a sea and tank assault was launched on the oil port of Ras Lanuf overnight, intensifying a counter-offensive against the out-gunned insurgents. [
]"Historically, those sort of events in the Middle East have tended to be quite supportive," said Michael Lewis, head of commodity research at Deutsche Bank.
"But the effect will probably fade quite quickly."
TAINTED
A generally stronger dollar <.DXY> also weighed on gold. The yen <JPY=> fell broadly and slumped to a two-week low against the dollar. A higher U.S. currency makes dollar-denominated commodities cheaper for holders of other currencies. [
]."There have been signs of some profit taking and scrap sales, but the market remains tight. Focus is concentrated on the Middle East; any sign of resolution will take some froth off the gold market," Standard Bank said in a note.
"Private investors have bought (silver) as a more affordable gold substitute, while professionals have remained keenly aware of silver's propensity to outperform in a bull market."
Silver <XAG=> was bid at $34.27 an ounce from $35.25 on Thursday, having rallied to a 31-year peak above $36 on Monday. Holdings of iShares Silver Trust <SLV> were unchanged at a record high at 10,974.06 tonnes.
"While clients we visited in the US and Canada over the past two weeks mostly wanted to talk about gold, we noted a clear upward shift in their interest in silver," UBS said in a note.
"There is little doubt that gold has lost some of its previous supporters to silver. Of those clients able to invest in the metal itself, rather than being restricted to silver equities, close to half were extremely bullish on silver's prospects."
Spot platinum <XPT=> was at $1,762.24 an ounce from $1,760.24 on Thursday and palladium <XPD=> at $746.50 an ounce from $765.50 an ounce.
"The appeal of (platinum and palladium) has been tainted by people worrying about the rise in oil prices and the impact on economic growth," a trader said.
(Editing by Jane Baird and Alison Birrane)