SINGAPORE, June 19 (Reuters) - Asian gasoil margins rebounded to a three-month high on Wednesday as spot demand from Vietnam emerged, even as Indonesia stepped up its own purchases, traders said.     The July gasoil crack gained 51 cents to $18.01 a barrel, the highest since March 18 when it was at $18.15 a barrel, Reuters data showed.      Vietnam's Petrolimex is seeking a spot gasoil cargo for July after recently buying a late-June cargo, industry sources said.     While output from domestic refinery Dung Quat is said to be stable, domestic demand might have increased slightly with the company also having to cover a shortfall after a fire at Okinawa refinery caused supply disruptions.     Diesel exports from Thailand have also been lower than usual due to planned maintenance by PTT and an unplanned outage at a hydrocracker unit at Bangchak Petroleum, traders said.     Spot demand from Indonesia has also been supporting high sulphur gasoil premiums. Recent spot purchases by the company could have been done at a premium of about $3 a barrel, traders said, though it was not clear who the suppliers were.      Sinopec Corp, Asia's largest refiner, has from the end of May cut the sulphur content of diesel agricultural, industrial and shipping use as part of a national effort to help clear Chinese cities of smog.     The refiner cut the sulphur content of its ordinary diesel to a maximum 350 ppm, bringing it in line with the minimum standard for diesel produced for autos and trucks, it said in a release.      The new standard also means a quality change in Sinopec's diesel exports, although the refiner is not expected to export any of the fuel in June for the second month in a row. Sinopec is the country's dominant diesel exporter.  
  ID:nL3N0EU22E
       Sinopec could likely resume exports of diesel in July, an industry source said, though this could not immediately be confirmed.      In the Singapore trading period, the first likely gasoil cargo to be loaded from Tanjung Bin was sold from Vitol to Hin Leong on Tuesday, traders said.      The oil terminal in southern Malaysia was approved in price agency Platts' assessment process late last year, though traders had been sceptical to lift cargoes from the terminal due to a lack of liquidity and additional port charges.          Saudi Aramco has bought all its requirements for June and July and is currently mulling volumes needed for August, industry sources said.     The company likely imported near record high diesel this year due to a rise in domestic demand and soaring temperatures which increases the use of air-conditioning, they added.       More ultra-low sulphur diesel spot supply was seen from the Gulf with Abu Dhabi National Oil Company offering a July 10ppm sulphur diesel cargo, after recently purchasing a June cargo from ENOC, traders said.     The premium was likely to be almost $3.50 a barrel above Middle East quotes, one said, although this could not be confirmed.          * TENDERS: Petrolimex is seeking 35,000 tonnes of 500 ppm sulphur gasoil for July 14 to 20. The cargo is to be loaded from Singapore, Thailand, South Korea, South China or Taiwan. The tender closes on June 21 and is valid until June 24.     - Bahrain Petroleum has offered 40,000 to 60,000 tonnes of jet fuel for July 27 to 30 loading. The tender closes on June 20.     - ADNOC has offered 40,000 tonnes of 10 ppm sulphur diesel for July 13 to 15 loading. The tender closes on June 24.              * SINGAPORE CASH DEALS: No jet trades, one gasoil deal.     - Hin Leong bought 150,000 barrels of 500 ppm sulphur gasoil for loading over July 15 to 19 from Tanjung Bin from Vitol at a premium of $1.50 a barrel.            MID-DISTILLATES                                                                 CASH ($/T)         ASIA CLOSE      Change  % Change   Prev     RIC                                                        Close      Spot Gas Oil 0.5%          120.49    1.39       1.17   119.10   
  GO-SIN
    GO 0.5 Diff                 -0.30    0.20     -40.00    -0.50   
  GO-SIN-DIF
    Spot Gas Oil               122.06    1.59       1.32   120.47   
  GO25-SIN
    0.25%                                                            GO 0.25 Diff                 1.07    0.20      22.99     0.87   
  GO25-SIN-DIF
    Spot Gas Oil               122.47    1.52       1.26   120.95   
  GO005-SIN
    0.05%                                                            GO 0.05 Diff                 1.48    0.13       9.63     1.35   
  GO005-SIN-DIF
    Spot Gas Oil               122.94    1.44       1.19   121.50   
  GO10-SIN
    0.001%                                                           GO 0.001 Diff                1.95    0.05       2.63     1.90   
  GO10-SIN-DIF
    Spot Jet/Kero              119.99    1.05       0.88   118.94   
  JET-SIN
    Jet/Kero Diff               -0.05   -0.05     NA         0.00   
  JET-SIN-DIF
                                                                                    SWAPS  ($/T)       ASIA CLOSE      Change  % Change   Prev     PM (1130 GMT)                     (0830 GMT)                         Close      Brent M1                   106.17    0.94       0.89   105.23   
  BRENTSGMc1
    Gasoil M1                  120.90    1.40       1.17   119.50   
  GOSGSWMc1
    Gasoil M1/M2                 0.70    0.10      16.67     0.60   
  GOSGSPDMc1
    Gasoil M2                  120.20    1.30       1.09   118.90   
  GOSGSWMc2
    Regrade M1                  -0.87   -0.30      52.63    -0.57   
  JETREGSGMc1
    Regrade M2                  -0.24   -0.19     380.00    -0.05   
  JETREGSGMc2
    Jet M1                     120.03    1.10       0.92   118.93   
  JETSGSWMc1
    Jet M1/M2                    0.07   -0.01     -12.50     0.08   
  JETSGSPDMc1
    Jet M2                     119.96    1.11       0.93   118.85   
  JETSGSWMc2
    Gasoil                      18.01    0.51       2.91    17.50   
  GOSGCKMc1
    500ppm-Dubai                                                     Cracks M1                                                        Gasoil                      17.71    0.38       2.19    17.33   
  GOSGCKMc2
    500ppm-Dubai                                                     Cracks M2                                                        Jet Cracks M1               17.14    0.24       1.42    16.90   
  JETSGCKMc1
    Jet Cracks M2               17.47    0.21       1.22    17.26   
  JETSGCKMc2
    East-West M1                 2.53    0.05       2.02     2.48   
  LGOAEFSMc1
    East-West M2                -2.26    0.23      -9.24    -2.49   
  LGOAEFSMc2
    LGO M1                     898.25   10.75       1.21   887.50   
  LGOAMc1
    LGO M1/M2                    0.50    1.00         NA    -0.50   
  LGOASPDMc1
    LGO M2                     897.75    9.75       1.10   888.00   
  LGOAMc2
    Crack LGO-Brent             14.33    0.37       2.65    13.96   
  LGOACKMc1
    M1                                                               Crack LGO-Brent             14.76    0.30       2.07    14.46   
  LGOACKMc2
    M2                                                                 (Reporting by Jessica Jaganathan; editing by James Jukwey)  ((jessica.jaganathan@thomsonreuters.com)(+65 6870 3822)(Reuters Messaging: jessica.jaganathan.thomsonreuters.com@reuters.net))  Keywords: MARKETS DISTILLATES/ASIA