The Netherlands’ base oils output slipped to a six-month low in November, coinciding with a drop in Europe’s imports from markets producing Group II base oils.Lower output and a drop in regional imports slashed Europe's supply of the premium-grade base oils to a seven-month low.An unusual surge in the Netherlands’ domestic demand for base oils and lubricants deepened the drop in supply.Lower supply helped to cushion against a drop in Europe’s lube demand at year-end as a seasonal slowdown compounded a protracted slide in consumption.The dynamic raised the prospect of curbing the size of any build-up of surplus supplies at the end of last year, leaving the market more balanced at the start of this year.The Netherlands’ base oils output held firm at 92,000 tonnes in November, government data showed.It still fell from more than 100,000 tonnes the previous month to the lowest since last May.The Netherlands is home to Europe’s sole virgin Group II base oils plant.Lower output in November contrasted with a surge in domestic demand to close to 150,000 tonnes.Most of the demand was categorized as “transformation in oil products” rather than finished lube consumption. A fall in Europe’s base oils imports from countries producing Group II base oils compounded the impact of lower output and higher domestic demand.Those imports, combined with the Netherlands’ output, fell to less than 139,000 tonnes in November.The volume dipped from more than 184,000 tonnes the previous month to the lowest since last April, when plant maintenance work was still taking place.Including the Netherlands’ consumption for transformation in oil products, Europe’s supply fell to little more than 5,000 tonnes in November.The volume was down from close to 100,000 tonnes the previous month and from more than 150,000 tonnes in each of the previous five months to September.The drop in supply coincided with firmer Europe Group II light-grade base oils prices relative to Group I prices since second-half November.Europe's Group II heavy-grade prices surged relative to Group I prices from around the middle of last year and held onto most of those gains since then..Spain’s November base oils output falls.Europe’s Nov Group III supply rises.US’ Nov base oils exports to Europe rise