US gasoline stocks rose by 908,000 barrels, well above analysts' expectations in a Reuters poll for a 256,000 barrels gain, putting exports from Europe in question.
Still, demand in Asia and the Middle East underpinned margins.
Heavy refinery maintenance in the Middle East has boosted its interest in Europe's exports.
Consultants Energy Aspects said that this had coincided with production problems at Iran's South Pars gas field that "seems to have" cut runs at the 120,000 bpd first phase of the Persian Gulf Star condensate splitter.
"Gasoline cracks are still stronger on a seasonal basis than they have been for several years and timespreads suggest barrels are not always so easy to come by," Energy Aspects said in a note, adding that stocks in the United States were building "from a substantially lower starting point than last year."
European petrochemical demand for naphtha has also been strong, due in part to high LPG prices.
Some 1.3 million tonnes of Western naphtha could land in Asia in November, sources told Reuters, the highest since July. Still, it would still be outstripped by demand of 1.5 million tonnes.
OPEC is leaning towards extending a deal with Russia and other non-members to cut oil supply for a further nine months, four OPEC sources said, although stronger-than-expected demand growth may allow the group to delay a decision until early next year. GASOLINE
Gunvor sold to BP a barge of eurobob gasoline at $550 a tonne fob ARA, up from a trade the previous day at $548 a tonne.
Earlier in the day, 4,000 tonnes traded at $553 a tonne fob Amsterdam-Rotterdam, compared with trades at $549-$551 a tonne on Tuesday. Total sold both to Varo.
There were no trades of premium unleaded gasoline.
The November swap stood at $546 a tonne at the close, up 50 cents from the previous day.
The benchmark EBOB gasoline refining margin edged up to $7.76 a barrel from $7.35 a barrel on Tuesday.
Brent crude futures were flat at $57.88 a barrel at 1536 GMT.
US front-month RBOB gasoline futures were down 0.55 percent at $1.6212 a gallon.
The RBOB crack versus US crude <RBc1-CLc1> was 1.99 percent lower at $16.25 a barrel.
NAPHTHA
No naphtha cargoes traded. Gunvor and Statoil bid to $515 cif NWE, while NP offered at $517 a tonne and Vitol at $519 a tonne.