SINGAPORE, Aug 6 (Reuters) - Asia diesel spot trading liquidity thinned as traders assessed forward supply-demand fundamentals against a backdrop of a weaker paper market structure.

Traders continued to express their concerns about tightening supplies in forward markets given lowered production from planned refinery maintenance, though front-month markets remain under pressure because of tepid regional demand.

Sellers are hoping for premiums in September spot sales, though it remains to be seen if discussions can hit such levels.

The front-month exchange of futures for swaps (EFS), typically known as the east-west spread, remained mostly at slightly above discounts of $30 per metric ton.

For August arrival to date, at least 200,000 metric tons of swing supplies from the Middle East and India are slated to arrive in Asia-Pacific, LSEG shipping data showed.

The 10ppm sulphur gasoil refining margins GO10SGCKMc1 slipped back to around $17.3 a barrel, reversing all of the previous session's gains.

Deals on the trading window were non-existent, with spot activity slowing down from the past two trading session. Cash differentials GO10-SIN-DIF declined in tandem with the weakening market structure for August-September.

Regrade JETREG10SGMc1 discounts narrowed to around $1.18 a barrel given the weakness in gasoil markets and slightly firmer front-month jet fuel markets.

SINGAPORE CASH DEALS O/AS

- No deal for both fuels

INVENTORIES

- U.S. crude and gasoline inventories fell last week, while distillate stockpiles rose, market sources said, citing American Petroleum Institute figures on Tuesday. API/S

- Middle distillates inventories held at Fujairah Oil Industry Zone gained to a three-week high of 2.276 million barrels as of August 4, according to industry information service S&P Global Commodity Insights. FUJAIRAH/

REFINERY NEWS REF/OUT

- Nigeria's Dangote oil refinery is planning a 15-day maintenance shutdown of its gasoline-making RFCC unit, tentatively starting on August 10, according to a note from industry monitor IIR seen by Reuters.

NEWS

- U.S. President Donald Trump said on Tuesday he would increase the tariff charged on imports from India from the current rate of 25% "very substantially" over the next 24 hours, in view of New Delhi's continued purchases of Russian oil.

- Chevron CVX.N and Valero Energy VLO.N are working to resume supplies of Venezuelan crude to Valero's U.S. refineries under an agreement that was on pause, three sources close to the preparations said on Tuesday, following a new license granted to the U.S. oil major.

- Russia's seaborne diesel and gasoil exports fell 5% in July from the month before to about 3.26 million metric tons due to lower production amid refinery maintenance and strong domestic demand, according to LSEG shipping data and market sources.

- Oil prices slipped on Tuesday as rising OPEC+ supply and worries of weaker global demand countered concerns about U.S. President Donald Trump's threats to India over its Russian oil purchases. O/R

PRICES

(Reporting by Trixie Yap; Editing by Harikrishnan Nair)

((trixie.yap@thomsonreuters.com;))