Commodities mostly rose this week as traders kept watch on simmering tensions in Ukraine, with star performer nickel striking a two-year peak on the back of supply woes.
President Vladimir Putin visited Crimea on Friday for the first time since Russia annexed the Ukrainian peninsula, ahead of a separatist vote by pro-Moscow militants in eastern Ukraine this weekend.
"The referendum in the Donetsk region is to go ahead on Sunday as planned despite Putin having called for it to be postponed," said Commerzbank analyst Carsten Fritsch.
"The crisis threatens to escalate once again if -- as expected -- a majority votes in favour of the region splitting from Ukraine."
OIL: The market rallied on Ukraine-linked supply risks and stronger-than-expected US crude demand, but ended the week on a stable note as some traders cashed in their gains.
"Oil prices pushed higher on both sides of the Atlantic amidst increased geopolitical risks after pro-Russian separatists in the Ukraine announced they would go ahead with an autonomy vote scheduled for eastern Ukraine this weekend," said Tradition Energy analyst Eugene McGillian.
"Additional support ... also appears to have come from increased concerns that Libya will not boost its oil exports after rebels that control two of Libya's oil export terminals announced they will not work with Libya's new Islamist-backed prime minister."
A full-blown armed conflict in Ukraine could disrupt supplies transported between Eastern Europe and the West and send energy prices rocketing.
The oil market had jumped Wednesday by more than $1 after US crude inventories unexpectedly fell from a record high last week, suggesting that demand may be picking up the world's leading crude consumer.
The US government's Department of Energy said crude reserves sank by 1.8 million barrels in the week to May 2. That confounded expectations for a gain of 1.2 million barrels, signalling solid demand.
By Friday on London's Intercontinental Exchange, Brent North Sea crude for delivery in June eased to $108.09 a barrel from $108.71 a week earlier.
On the New York Mercantile Exchange, West Texas Intermediate or light sweet crude for June jumped to $100.70 per barrel compared with $99.93.
- Nickel strikes 2011 peak -
BASE METALS: Star performer nickel surged on Friday to $20,500 per tonne, hitting the highest level since February 2012 following a supply outage at a huge mine in New Caledonia.
"A perfect storm appears to have blown up on the nickel market," said Fritsch at Commerzbank.
"Besides the ore export ban in Indonesia and the uncertainty over what would happen to Russian shipments in the event of far-reaching sanctions against the country, it was news from New Caledonia that rocked the nickel market.
"Vale, the world's second-largest nickel producer, had to shut down production in the nickel complex formerly known as Goro ... following an acid spill."
The facility, with a capacity of 60,000 tonnes per year, is one of the world's biggest nickel mines.
By Friday on the London Metal Exchange, copper for delivery in three months advanced to $6,736 per tonne from $6,648 a week earlier.
Three-month aluminium dropped to $1,765.50 a tonne from $1,775.25.
Three-month lead rose to $2,102.50 a tonne from $2,078.25.
Three-month tin increased to $23,120 a tonne from $22,930.
Three-month nickel soared to $20,100 a tonne from $18,150.
Three-month zinc gained to $2,040 a tonne from $2,012.
PRECIOUS METALS: Gold hit a three-week peak as Ukraine fears boosted demand for the precious metal, which is seen as a haven in times of geopolitical turmoil.
The glamorous metal rose as high as $1,315.70 per ounce on Monday, before pulling lower as Putin attempted to de-escalate tensions.
"Some buying has occurred on the back of Ukraine concerns, but for the moment we are still rangebound," said IG trader Brenda Kelly.
By Friday on the London Bullion Market, the price of gold rose to $1,291.25 an ounce from $1,281.25 on Friday of the previous week.
Silver increased to $19.25 an ounce from $19.17.
On the London Platinum and Palladium Market, platinum advanced to $1,429 an ounce from $1,425.
Palladium slipped to $804 an ounce from $816.
- Soft commodities mostly drop -
SUGAR: Prices fell, but losses were capped by weather-related supply concerns in Brazil.
"Futures remain in a trading range, with the potential for crop losses in Brazil providing support and the current oversupplied market conditions keeping sellers active," said analyst Jack Scoville at Price Futures Group.
By Friday on LIFFE, London's futures exchange, the price of a tonne of white sugar for delivery in August fell to $467.80 from $476.30 a week earlier.
On ICE Futures US, the price of unrefined sugar for July eased to 17.17 US cents a pound from 17.79 US cents.
COFFEE: The coffee market fell as traders set aside worries over drought-hit production in key producer Brazil.
"The situation regarding the (drought) damage to the coffee (crop) has not changed, however the tone of the market has for the moment turned a little negative and we will go through a period of weak prices," said Citi analyst Sterling Smith.
By Friday on the ICE Futures US exchange, Arabica for delivery in July fell to 192.45 US cents per pound from 204.65 cents a week earlier.
On LIFFE, Robusta for July dipped to $2,124 a tonne from $2,163.
COCOA: Futures slid to their lowest levels since late January, hit by speculative selling.
By Friday on LIFFE, cocoa for delivery in July dropped to £1,789 a tonne from £1,816 a week earlier.
On ICE Futures US, cocoa for July retreated to $2,873 a tonne from $2,914.
RUBBER: Prices in Kuala Lumpur fell on lacklustre demand, with sentiment dented also by poor manufacturing data from top consumer China.
The Malaysian Rubber Board's benchmark SMR20 fell to 166.75 US cents a kilo from 173.90 cents a week earlier.