Oil prices have extended declines amid deepening worries about how long it will take to cut back a global glut in supply.
Brent crude slipped below $47 a barrel in early trading on Friday to reach new five-month lows, having fallen from above $50 the day before.
Iron ore and copper markets also saw falls, and the drop in commodities helped pull Asian stock markets lower.
Signs of the market weakening again threatens to puncture renewed optimism in the sector – which has been shedding thousands of jobs after the collapse in the price from levels of more than $100 in 2014.
But it could cheer motorists, already benefiting after supermarkets cut petrol and diesel pump prices earlier this week.
Thursday’s fall in the price of Brent crude followed weak Chinese economic data – which might threaten demand from the fast-growing economy – and higher-than-expected US inventories, or stock piles of oil.
Markets had anticipated a faster decline in the glut of supply which had built up.
The weakness in the oil price worsened on reports that oil nations had appeared to rule out deeper cuts to production.
Brent crude was last lower at the end of November.
Oil had slumped to less than $30 a barrel earlier in 2016 but an agreement by the OPEC cartel and other countries had helped boost its recovery from those lows.