LONDON - Commodity prices faced some heavy selling this week as the spotlight fell on the impact of China’s stock market crash, while uncertainty over Greece added to the downward pressure.

“The idea that a stock market crash could put a hole in China’s economy and reduce demand from the world’s biggest resource-consumer is adding to the pain for commodities,” said CMC Markets analyst Jasper Lawler.

OIL: With prices already downbeat, the International Energy Agency (IEA) on Friday forecast that global oil demand growth would slow in 2016, and that crude production in nations outside the Organization of the Petroleum Exporting Countries (OPEC) would stall.

In its first estimates for 2016, the IEA forecast that oil demand would slow next year to 1.2 million barrels per day, compared with an average of 1.4 million barrels per day this year.

Meanwhile growth in non-OPEC oil supply “is expected to grind to a halt in 2016 as lower oil prices and spending cuts take a toll,” the IEA said in its monthly oil report. US crude futures had sunk nearly eight percent Monday on worries about slowing global growth, as Greek voters rejected a bailout offer and China moved to calm financial market turbulence. “There are some signs that foreign investors are more optimistic about China’s efforts to arrest the stock slide,” said Bernard Aw, market strategist at IG Markets.

“However, I feel much caution should be exercised and it is important to observe the Chinese markets in the coming sessions before calling it a bottom.”

Aw added: “As we have seen in the past, Chinese equities may recover in one session, only to fall straight back into a downward spiral the next day.”

Chinese stocks surged for a second day on Friday as a government rescue plan offered a respite from a month-long rout. In a rollercoaster week, the Shanghai market gained 5.18 percent overall, after the government announced additional policies to avoid a market crash.

But it is still down 24.9 percent from its closing peak on June 12.

The stock market slide of recent weeks was a dramatic reversal of a 150 percent charge in the 12 months to its peak last month, fuelled by tens of millions of retail investors using borrowed funds.

China’s economy, the world’s second largest, is already faltering. Gross domestic product expanded 7.4 percent in 2014, the slowest pace since 1990, and weakened further in the first three months of this year.

But the International Monetary Fund said Thursday that there was no reason to lose faith in China’s economy because of the bursting stock market bubble.

The oil market was focused also on Greece amid hopes debt-strapped nation would reach a deal with its creditors after Athens laid out details Thursday of a new bailout plan to save it from financial collapse. The package involves a pensions overhaul and tax hikes in return for debt relief and a rescue loan from the eurozone.

Traders are also keeping an eye on negotiations in Vienna between western powers and Iran on a deal to curb Tehran’s nuclear ambitions and allow the lifting of punishing sanctions.

A reprieve would allow Iranian oil to flow back into the global market, adding to a supply glut and helping depress prices, according to analysts. US commercial crude stockpiles rose another 400,000 barrels to 465.8 million barrels in the week to July 3, even as refineries picked up activity. Gasoline inventories also jumped, with the summer holiday driving season in full swing.

By Friday on London’s Intercontinental Exchange, Brent North Sea crude for delivery in August fell to $58.68 a barrel from $60.39 a week earlier.

On the New York Mercantile Exchange, West Texas Intermediate (WTI) or light sweet crude for August dropped to $52.74 a barrel from $55.41 a barrel.

PRECIOUS METALS: Gold led the precious metals complex lower.

“If the markets receive further indications that the Federal Reserve will leave interest rates unchanged... possibly even until December, then this would allow gold an opportunity to begin recovering the heavy losses of the past couple of months,” said Jameel Ahmad, chief market analyst at trading group FXTM.

The dollar has gained in recent months, not only from the Greek fallout, but also from expectations that the US central bank could start raising its key interest rate before the end of the year — making it a more attractive investment compared with gold, itself seen as a haven investment.

Federal Reserve Chair Janet Yellen reiterated her view Friday that the central bank will likely begin raising interest rates before the end of 2015.

“I expect that it will be appropriate at some point later this year to take the first step to raise the federal funds rate and thus begin normalizing monetary policy,” she said in a speech in Cleveland, Ohio.

By Friday on the London Bullion Market, the price of gold dropped to $1,159.30 an ounce from $1,167.95 a week earlier.

Silver fell to $15.45 an ounce from $15.64. On the London Platinum and Palladium Market, platinum slid to $1,029.30 an ounce from $1,083.

Palladium slumped to $649.35 an ounce from $701.

BASE METALS: Prices mostly declined as traders took their lead from China. “There is still some uncertainties about the supply and demand going forward,” said Saxo Bank analyst Ole Hansen.

“Commodities rely on growth and demand, and the demand is coming from China. If you look at base metals, somewhere between 40 to 50 percent of all metals are consumed by China. If demand slows this could have a significant impact on the supply demand situation,” he said. By Friday on the London Metal Exchange, copper for delivery in three months fell to $5,577.50 a tonne from $5,803 a week earlier.

Three-month aluminium dropped to $1,690.50 a tonne from $1,728. Three-month lead rose to $1,794.50 a tonne from $1,775. Three-month tin slid to $13,975 a tonne from $14,400. Three-month nickel declined to $11,275 a tonne from $12,125. Three-month zinc retreated to $2,005.50 a tonne from $2,025.

COCOA: London-traded cocoa hit a new four-year high at £2,206 a tonne as tight supplies offset macroeconomic concerns of risk weighing on demand.

By Friday on LIFFE, London’s futures exchange, cocoa for delivery in September edged up to £2,199 a tonne from £2,171 a week earlier.

By Thursday on the ICE Futures US exchange, cocoa for September grew to $3,293 a tonne from $3,288 on Thursday of the previous week, when US markets closed earlier than usual ahead of the July 4 Independence Day festivities.

SUGAR: Prices retreated owing to higher-than-expected Brazilian output, analysts said. By Friday on LIFFE, a tonne of white sugar for delivery in October slid to $358.60 compared with $372.60 for the August contract one week earlier. On ICE Futures US, unrefined sugar for October dropped to 12.05 US cents from 12.30 cents on Thursday of the previous week.

COFFEE: Prices struck an 18-month low in New York at 123.65 US cents a pound with supplies expected to be robust despite previous dry weather in Brazil.

By Thursday on ICE Futures US, Arabica for delivery in September fell to 126.80 US cents a pound from 127.40 cents on Thursday of the previous week.

By Friday on LIFFE, Robusta for September slipped to $1,732 a tonne from $1,744 one week earlier.

RUBBER: Prices declined as Malaysia’s currency slumped.

The ringgit hit a 16-year low point on growing political uncertainty following allegations that a probe into a state investment fund found hundreds of millions of dollars were transferred into the prime minister’s personal accounts.

The currency dropped 0.8 percent to 3.8088 against the greenback in Kuala Lumpur, the lowest level since May 1999.

On Friday, the Malaysian Rubber Board’s benchmark SMR20 fell to 145.25 US cents per kilo from 149.90 US cents a kilo one week ago.