LONDON, Dec 10 (Reuters) - European gasoline prices fell on Thursday, pressured by swelling stocks and a lack of export opportunities to the key U.S. market.

Gasoline stocks stored in independent tanks in ARA rose 43,000 tonnes to 849,000 tonnes in the week ending Thursday, according to an independent analyst. [ARA/]

Traders also said a firm that had recently been seen buying due to refinery maintenance had now stopped.

PRICES 

* Barges of 10ppm premium unleaded gasoline fell to $635-$638 a tonne fob ARA, down from $642-$643 on Wednesday and at new two-month lows.

* Liquidity was subdued with around 14,000 tonnes changing hands, down from 25,000 tonnes the previous day.

* Eurograde crack spreads BFO- rose to around $4.83 a barrel from a two-month low of $3.65 on Wednesday.

* Brent crude futures LCOc1 were trading 91 cents lower at $71.48 by 1806 GMT.

SWAPS  

* Gasoline barge swaps edged up to $658.75 a tonne fob ARA for the balance of December and the contango held at around $10.

* Arbitrage swaps for December were steady at $1.40 a tonne and $1.20 for January but trade sources have not reported any recent bookings for vessels to the United States.

* Some exports have gone to Mexico, Nigeria and West Africa this month.

NAPHTHA

* No cargoes changed hands in the public trading window.

* Swaps held in backwardation at the front of the curve but the front intermonth spread fell to around $6 from $8 on Wednesday.

* On a crack basis, refiners can expect to make a profit from making naphtha in both December and January. The December crack spread rose to over $2 a barrel, swaps showed.

* But traders said that even if refinery output rises in Europe on better margins, the surplus product is likely to be shipped east to meet resurgent demand in Asia. (Reporting by Emma Farge; editing by Veronica Brown)