* Buys nearly 9 million barrels gasoil for Oct-Nov so far

* Winson Oil's trades accounts for 40 percent of total

* Likely for North Asian bunker market - traders

By Jessica Jaganathan

SINGAPORE, Nov 8 (Reuters) - Oil trader Winson Oil is snapping up massive volumes of gasoil in Asia's oil trading hub in Singapore, which has helped push up margins for the industrial and transport fuel to a nearly one-year high.

Since the middle of September, Winson has bought over 2.3 million barrels of 500 ppm sulphur gasoil for loading from Singapore or southern Malaysia in October during the Platts Market-on-Close assessment process, according to Reuters calculation based on daily trade data.

Winson, based in Hong Kong and registered in Singapore, also purchased 6.3 million barrels for loading in November and 300,000 barrels for December during the same time period, the data showed.

This accounts for about 40 percent of overall gasoil trades during that time, the data showed.

Since the buying surge began, margins for gasoil in Singapore have gained 20 percent, reaching $12.69 a barrel on Tuesday.

Winson Oil was not available for comment on the matter but a company executive, who declined to be identified since he is not authorized to speak to the media, said the cargoes were for trading purposes, declining to elaborate further.

Winson is likely using the cargoes to fulfil North Asian demand for bunker, or shipping fuel, at least five traders said.

Marine gasoil (MGO), used in large vessels like container ships and tankers, is used to run the ships to reduce emissions while they are near ports.

Winson Oil also has term agreements in Taiwan and South Korea to lift about 4 million barrels of gasoil a month, one of the traders said.

The company has stepped up its trading in Singapore, routinely buying gasoil from Taiwan and selling it as bunker fuel into North Asia.

It also supplies gasoil to the Philippines, Vietnam, Indonesia and Hong Kong, a second trader said.

Winson bought its first very large crude carrier (VLCC) in July to store gasoil offshore and expand into the European and African market.

"To fulfil the VLCC is actual demand I think," the second trader added.

China's bunker market demand has risen amid increased coal imports and container exports, a North Asian trader said.

China's MGO market is currently at about $550 a tonne, compared with about $420 in Singapore, which could be drawing barrels there, the trader added.

"This is a big price gap so it could be why they are buying as much gasoil as possible," the trader added.

The North Asian bunker market imports about 200,000 tonnes, or about 1.5 million barrels, of gasoil every month, with Winson being the biggest supplier, the traders said.

Platts, a unit of S&P Global, competes with Thomson Reuters in providing information to energy markets.

(Reporting by Jessica Jaganathan; Editing by Christian Schmollinger) ((Jessica.Jaganathan@thomsonreuters.com; +65 6870 3822; Reuters Messaging: jessica.jaganathan.thomsonreuters.com@reuters.net))

Keywords: SINGAPORE OIL/TRADE