* Coronavirus cases jump in South Korea, Italy and Iran
* China braces for big economic hit from virus, says Xi
* Four Chinese provinces lower emergency response (Updates prices, market activity, adds commentary; changes byline, dateline, previous LONDON)
NEW YORK, Feb 24 (Reuters) - Oil prices slumped by 5% on Monday as the rapid spread of the coronavirus in countries outside China added to investor concerns over the effect on demand for crude.
Global equities also extended losses as worries about the impact of the virus grew, with the number of cases jumping in Iran, Italy and South Korea.
Brent crude futures fell $2.96, or 5.1%, to $55.54 a barrel. U.S. West Texas Intermediate (WTI) crude futures dropped by $2.58, or 4.8%, to $50.80 a barrel.
"As the virus spreads globally, additional downside revisions in oil demand for this year may be required," Jim Ritterbusch, president of Ritterbusch and Associates, said in a note.
"The accelerated sell-off in the stock market has become difficult for the oil market to ignore," he added.
The coronavirus has infected nearly 77,000 people and killed more than 2,500 in China, most of them in Hubei.
South Korea's fourth-largest city, Daegu, was increasingly isolated as the number of infections there rose rapidly.
Europe's biggest outbreak is in Italy, which reported a seventh death from the flu-like virus and 220 infections.
Kuwait, Bahrain, Oman and Iraq on Monday recorded their first new coronavirus cases, all involving people who had been in Iran, which raised its toll from the disease to 12 dead and 61 infected.
Afghanistan, Iraq, Kuwait, Saudi Arabia and Turkey imposed travel and immigration curbs on Iran.
"We should not underestimate the economic disruption, as a super spreader could trigger a massive drop in business activity around the globe," Stephen Innes, chief market strategist at AxiCorp, said in a note.
Still, World Health Organization chief Tedros Adhanom Ghebreyesus said that using the word "pandemic" did not fit the facts. "We must focus on containment while preparing for a potential pandemic," he told reporters in Geneva, adding that the world was not witnessing an uncontained spread or large-scale deaths.
On Monday local health officials in China said that four provinces had lowered their virus emergency response measures.
Chinese President Xi Jinping on Sunday said that the world's largest energy consumer will adjust policy to help to cushion the economic impact from the virus outbreak.
Goldman Sachs said commodity prices could fall sharply before any rebound on the back of Chinese stimulus efforts.
"The promise of stimulus has made commodity markets act like equity markets, building up risks of a sharp correction," the bank said in a note.
Bank of America Global Research kept its 2020 forecast for the price of Brent crude steady at $62 a barrel, citing voluntary and involuntary declines in OPEC supply and the resilience of markets to geopolitical shocks. (Reporting by Noah Browning in London and Jessica Jaganathan in Singapore; Editing by Marguerita Choy and Jason Neely)