LONDON - Commodity prices traded mixed this week as dealers took their cue from a backdrop of weak global economic growth and geopolitical tensions, notably in the Middle East.

OIL: Crude oil prices retreated as a weak energy demand situation offset potential supply risks caused by geopolitical tensions fuelled by Israeli air strikes in the Gaza Strip. Prices were lower overall despite a mid-week bounce on the back of the Middle East violence. Gaza militants fired rockets at both Jerusalem and Tel Aviv on Friday aiming for the Jewish state’s political and commercial hearts, prompting Israel to call up thousands more reservists in readiness for potential ground operations.

The military wing of the Islamist Hamas movement which rules Gaza said it fired a rocket at Jerusalem, the first to strike the outskirts of the Holy City in the history of the Israeli-Palestinian conflict. It marked a major escalation by the territory’s Hamas rulers in the face of a deadly pounding since Wednesday by Israeli aircraft that has killed 23 Gazans and sparked outrage across the Arab and Islamic world.

The bloodshed began on Wednesday when Israel killed top Hamas military chief Ahmed Jaabari in an air strike on a car in Gaza City.

Oil prices fell at the start of the week as the International Energy Agency cut its global crude demand forecasts, while sentiment has also been hit by worries over the looming US “fiscal cliff” and the ongoing eurozone debt crisis.

US President Barack Obama on Friday attempted to avert a looming combination of automatic tax hikes and spending cuts in the world’s biggest economy. If the package of measures comes in as planned on January 1, the United States, which is also the world’s biggest oil consuming nation, will likely tip back into recession, which would have a devastating effect globally.

By Friday on the New York Mercantile Exchange, West Texas Intermediate (WTI) or light sweet crude for December dipped to $85.09 a barrel from $85.74 a week earlier. On London’s Intercontinental Exchange, Brent North Sea crude for delivery in January stood at $107.83 a barrel compared with $108.23 for the expired December contract a week earlier.

PRECIOUS METALS: Gold prices fell as the World Gold Council said global demand for the metal had dropped 11 per cent in the third quarter on an annual basis, with buying in key market China dipping because of its slowing economy.

Worldwide demand fell year-on-year in the July-September period to 1,084.6 tonnes worth an estimated $57.6 billion as prices on average were 3.0 per cent lower than the record levels seen a year earlier, the WGC’s latest report said.

Platinum futures eased as weak demand expectations helped offset a prediction by industrial group Johnson Matthey that world output of the metal would slide by 10 per cent this year owing to unrest at South African mines.

“Platinum has shed its gains... following Johnson Matthey’s publication of its market report,” analysts at Commerzbank said in a note to clients.

Anglo American Platinum this week said workers had returned to its South Africa mines after accepting a new wage offer, ending a two-month strike that crippled production.

It was the last major mining firm still grappling with an industrial action after a wave of illegal South African strikes led to more than 50 deaths, including 34 people shot dead by police at platinum miner Lonmin in August.

By late Friday on the London Bullion Market, gold fell to $1,713.50 an ounce from $1,738.25 a week earlier.

Silver rose to $32.27 an ounce from $32.16. On the London Platinum and Palladium Market, platinum dipped to $1,554 an ounce from $1,559. Palladium grew to $623 an ounce from $612.

BASE METALS: Base or industrial metal prices rose across the board, while traders reacted to news that China’s all-powerful Communist Party had unveiled a new seven-man leadership council to take command for the next decade.

China, the world’s second biggest economy, is a major consumer of commodities and especially base metals.

By late Friday on the London Metal Exchange, copper for delivery in three months climbed to $7,581 a tonne from $7,534 a week earlier.

Three-month aluminium grew to $1,936 a tonne from $1,907.

Three-month lead gained to $2,147 a tonne from $2,141.

Three-month increased to $20,390 a tonne from $20,250.

Three-month nickel advanced to $16,023 a tonne from $15,970.

Three-month zinc improved to $1,921 a tonne from $1,889.

COCOA: Prices rallied as Ivory Coast President Alassane Ouattara on Wednesday dissolved the top cocoa producing nation’s government that had formed in March after the political and military crisis of 2010-2011.

The head of the president’s office, Amadou Gon Coulibaly, said the dissolution was the consequence of differences among the governing parties—Ouattara’s RDR, former president Henri Konan Bedie’s PDCI and the small UDPCI party.

“We regard the price rise to be merely temporary in nature, however, and view fears of supply shortfalls as unfounded,” said Commerzbank analyst Carsten Fritsch.

“Even when Ivory Coast was on the brink of civil war following the presidential elections in early 2011 and the current president imposed an export ban, the supply of cocoa was not hampered. On the contrary, the Ivory Coast cocoa harvest yielded a record 1.5 million tonness in the 2010/11 crop year.”

Top movers and shakers in the cocoa industry were meanwhile set to descend upon Ivory Coast’s capital city Abijan on Monday for a world cocoa conference.

By Friday on LIFFE, London’s futures exchange, cocoa for delivery in March jumped to £1,593 a tonne from £1,524 a week earlier. On New York’s NYBOT-ICE exchange, cocoa for March grew to $2,465 a tonne from $2,340 a week earlier.

COFFEE: Arabica coffee struck the lowest level since June, 2010 — at 149.45 US cents a pound—while Robusta-quality beans hit a nine-month trough at $1,891 a tonne on expectations of plentiful supplies.

By Friday on NYBOT-ICE, Arabica for delivery in March rose to 153.6 US cents a pound from 151.45 a week earlier.

On LIFFE, Robusta for January slid to $1,914 a tonne from $1,971 a week earlier.

SUGAR: Prices in London slumped to 2.5-year lows at $506.10 a tonne on high production forecasts.

By Friday on LIFFE, the price of a tonne of white sugar for delivery in March dropped to $507.80 from $526 a week earlier.

On NYBOT-ICE, the price of unrefined sugar for March rose to 19.11 US cents a pound from 18.83 cents the previous week.

GRAINS AND SOYA: Maize, wheat and soya prices fell, hit by US economic weakness and high output expectations, traders said.

By Friday on the Chicago Board of Trade, maize for delivery in December dropped to $7.14 a bushel from $7.38 a week earlier.

January-dated soyabean meal—used in animal feed—retreated to $13.75 a bushel from $14.52. Wheat for December decreased to $8.34 a bushel from $8.86.

RUBBER: Prices inched higher on reports China had increased its rubber reserves and as major producers reduced exports. The Malaysian Rubber Board’s benchmark SMR20 ended at 277.90 US cents a kilo, up from 276.00 cents the previous week.