SINGAPORE, April 17 (Reuters) - Asia's middle distillates markets gain further, but overall window trading activity thinned on the last trading day of the week and refiners still sold May spot cargoes at discounts.

The market saw a lack of window deals for the third straight session, though 10ppm sulphur gasoil buying interest picked up momentum through the course of the week.

Various spot cargoes were sold at discounts through the week, ranging from 20 cents to 60 cents per barrel.

The 10ppm sulphur gasoil refining margins GO10SGCKMc1 remained slightly above $14 per barrel, little changed from a week earlier.

On Friday, spot cash differentials GO10-SIN-DIF barely moved from the previous trading session, maintaining at their highest since slightly more than a month ago at a premium of around 57 cents per barrel.

On the jet fuel front, some buying interest on the trading window provided support to spot differentials with the value closing at the highest for the week of 48 cents premium per barrel.

Regrade JETREG10SGMc1 widened to the week's highest discount of slightly more than $1.05 a barrel, reflecting sharper gains in diesel paper markets.

SINGAPORE CASH DEALS O/AS

- No deals for both fuels

INVENTORIES

- U.S. crude stocks rose last week despite a major increase in exports, while fuel inventories fell, the Energy Information Administration said on Wednesday. EIA/S

- Singapore's middle distillates stock levels gained for a second straight week amid a rise in overall imports of diesel/gasoil, official data showed on Thursday. O/SING1

REFINERY NEWS REF/OUT

- Valero Energy Corp VLO.N said on Wednesday it was taking a $1.1 billion pre-tax impairment related to its California refineries and told state regulators it would permanently shut or restructure its San Francisco-area refinery in Benicia, California by the end of April 2026.

- Motiva Enterprises [RIC:RIC:MOTIV.UL] restarted the gasoline-producing fluidic catalytic cracker $(FCC.AU)$ at its 626,000 barrel-per-day (bpd) Port Arthur, Texas refinery, people familiar with plant operations said on Wednesday.

NEWS

- The Organization of the Petroleum Exporting Countries (OPEC) has received updated plans for Iraq, Kazakhstan and other countries to make further oil output cuts to compensate for pumping above agreed quotas, the group said on Wednesday.

- Russia's exports of Arctic oil to China are set to rise sharply in April after sellers offered wide discounts and shipment on non-sanctioned tankers to counter a U.S. embargo, analytics firm Vortexa and two Russian oil traders said.

- Oil prices extended gains on Thursday on the prospect of tighter supply after Washington imposed further sanctions to curb Iranian oil trade and as some OPEC producers pledged more output cuts to compensate for pumping above agreed quotas. O/R

PRICES

(Reporting by Trixie Yap; Editing by Shinjini Ganguli)

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