SINGAPORE (Reuters) - The suspension of flights to China by global airlines due to the coronavirus epidemic resulted in Asian refining margins for jet fuel in January showing their biggest monthly decline in a more than a decade.

FILE PHOTO: A passenger in a protective mask uses her phone at Rome's Fiumicino airport, after first cases of coronavirus were confirmed in Italy, January 31, 2020. REUTERS/Yara Nardi/File Photo

Refining margins or cracks for jet fuel JETSGCKMc1 dropped 34% in January, their biggest monthly drop according to data going back to as far as April 2009, Refinitiv Eikon showed.

Cracks for the aviation fuel, which closed at $9.61 a barrel over Dubai crude on Friday, have shed 17% in the last week alone, the Refinitiv data showed.

(GRAPHIC: Asia jet fuel margins post biggest-ever monthly drop as coronavirus slams aviation demand - )

The death toll from the coronavirus, which originated from Chinese city of Wuhan, has risen to 361 and has spread to more than two dozen other countries, while the World Health Organization has declared the outbreak a public health emergency of international concern.

“Currently in China, travel tours (both domestic and international) have all been suspended. Major flight routes might be maintained to cater to remaining demand but airlines will likely reduce flight frequencies to save cost. This will impact jet demand significantly,” said Sandy Kwa, analyst at energy consultancy FGE.

“Keeping a conservative outlook, the Wuhan coronavirus will heavily dampen air travel in the near future, but should gradually recover in the summer holiday travel period, barring any worsening of the virus outbreak or radical changes in government policies.”

The health scare became heightened over Lunar New Year, a peak traveling season in large parts of Asia, but this year passengers were forced to call off travel plans and airlines offered refunds.

During the 2002-2003 outbreak of Severe Acute Respiratory Syndrome (SARS) - also caused by a coronavirus that originated in China that killed nearly 800 people globally - air passenger demand in Asia plunged 45%.

At present, the travel industry is even more reliant on Chinese travelers.

Jet demand is expected to fall within a range of 170,000-300,000 barrels-per-day due to the travel curbs, according to analyst estimates.

Asia's largest refiner Sinopec 0386.HK is cutting throughput this month by around 600,000 barrels per day (bpd) due to weaker fuel demand.

A Singapore-based trader said Sinopec’s production cut would help balance the market, but he expected demand to remain weak as the health scare would have a big, fundamental impact for the short to medium term.

The aviation fuel market also remains under pressure as a warmer than usual winter in northeast Asia this year has reduced the usual seasonal increase in demand for heating kerosene, which is closely-related to jet fuel.