By Amanda Cooper
LONDON (Reuters) - Oil prices fell on Monday, dented by the rise in the U.S. dollar to seven-month highs, and analysts see more losses triggered by the mismatch between global supply and demand.
The fall was part of a wider decline in commodities that has also been stoked by worries over faltering demand from China, with prices for base metals such as copper and nickel tumbling. However, speculators have turned increasingly negative on crude.
U.S. West Texas Intermediate (WTI) crude futures fell $1.26 a barrel to $40.64 a barrel by 0918 GMT. The contract broke below $40 on Friday for the first time since August.
Benchmark January Brent futures were last down 90 cents at $43.76 a barrel.
"That seven-month high (in the dollar) flashed a warning sign in people's faces that the dollar is appreciating," CMC Markets analyst Jasper Lawler said.
The U.S. Federal Reserve is widely expected to deliver its first rate rise in almost a decade when it meets next month, while the European Central Bank looks almost certain to continue to ease monetary policy.
A stronger dollar (DXY) tends to make it more profitable for non-U.S. investors to sell their dollar-denominated commodity holdings.
The break in U.S. crude futures below $40 a barrel exacerbated the pace of the selling, CMC's Lawler said.
"Half of what is happening in WTI is just because we've broken that $40 level after holding above it for so long, so Brent has got to follow through ... the main target is the (August) low ... that's on the cards this week," he said.
Big hedge funds have increased their bets that oil will continue to fall, according to data from the U.S. Commodity Futures Trading Commission (CFTC) last week.
Speculators now hold more positions that are betting on a drop in the oil price than at any time since at least 2009, according to Reuters data.
Meanwhile, Venezuela's oil minister said on Sunday that OPEC cannot allow an oil price war and must take action to stabilise the crude market soon. When asked how low oil prices could go in 2016 if OPEC doesn't change its policy, he said: "Mid-20s."
Oil prices have halved over the last 12 months after OPEC decided to maintain its production levels, or even increase them, to retain market share, in part by forcing higher-cost producers elsewhere to cut output.
Oil markets were keeping an eye on developing geopolitical tensions in the Middle East as Jordan's King Abdullah will hold talks with Russian President Vladimir Putin on how to tackle "terror groups" led by Islamic State in Syria, an official source said.