SINGAPORE, Dec 17 (Reuters) - Asia"s cash premiums for jet fuel rose on Friday, posting a weekly gain on a gradual uptick in aviation demand, but global airlines were keeping a close eye on the increasing Omicron coronavirus cases that may dampen further recovery. The regional jet fuel market, however, would remain partly supported by the seasonal heating demand for kerosene during the peak winter months in Japan, market watchers said. Cash premiums for jet fuel rose to 75 cents per barrel to Singapore quotes, the highest since May 2018. The differentials were at a 58-cent premium on Thursday, and have more than doubled this week. Refining margins, also known as cracks, for jet fuel dipped to $11.52 per barrel over Dubai crude during Asian trading hours, 6 cents lower from a day earlier. The cracks have slipped 1.8% this week. ARA INVENTORIES - Gasoil stocks held independently in the Amsterdam-Rotterdam-Antwerp (ARA) refining and storage hub dropped 10.3% to 1.7 million tonnes in the week ended Dec. 16, according to Dutch consultancy Insights Global. - Weekly gasoil demand up the Rhine River soared to the highest level since mid-2020, as buyers took advantage of high water levels and stocked up ahead of the holiday season, according to Insights Global"s Lars van Wageningen. - ARA jet fuel inventories fell 3.8% this week to 870,000 tonnes. SINGAPORE CASH DEALS - No jet fuel trades, no gasoil deals OTHER NEWS - Oil prices dipped on Friday, putting the market on track for a weekly loss, as surging cases of the Omicron coronavirus variant raised fears new curbs may hit fuel demand, while a weaker dollar supported commodity markets broadly. - Indian and Chinese oil buyers are snapping up Middle East crude after spot premiums for February-loading cargoes slumped by more than half to three-month lows on improved supplies to Asia. read more ASSESSMENTS MID-DISTILLATES CASH ($/T) ASIA CLOSE Change % Change Prev Close RIC Spot Gas Oil 0.5% 84.66 -0.2 -0.24 84.86 GO 0.5 Diff -1.08 -0.02 1.89 -1.06 Spot Gas Oil 0.25% 84.87 -0.2 -0.24 85.07 GO 0.25 Diff -0.87 -0.02 2.35 -0.85 Spot Gas Oil 0.05% 85.27 -0.2 -0.23 85.47 GO 0.05 Diff -0.47 -0.02 4.44 -0.45 Spot Gas Oil 0.001% 86.36 -0.21 -0.24 86.57 GO 0.001 Diff 0.62 -0.03 -4.62 0.65 Spot Jet/Kero 84.75 0.1 0.12 84.65 Jet/Kero Diff 0.75 0.17 29.31 0.58 For a list of derivatives prices, including margins, please double click the RICs below. Brent M1 Gasoil M1 Gasoil M1/M2 Gasoil M2 Regrade M1 Regrade M2 Jet M1 Jet M1/M2 Jet M2 Gasoil 500ppm-Dubai Cracks M1 Gasoil 500ppm-Dubai Cracks M2 Jet Cracks M1 Jet Cracks M2 East-West M1 East-West M2 LGO M1 LGO M1/M2 LGO M2 Crack LGO-Brent M1 Crack LGO-Brent M2