SINGAPORE - China's exports of clean marine bunker, or very low-sulphur fuel oil (VLSFO), dipped 2% in August from a year-ago period, customs data showed on Monday.

August exports of the shipping fuel, which has a maximum sulphur content of 0.5% to comply with emission rules set by the International Maritime Organization (IMO), were at 1.59 million tonnes, compared with 1.77 million tonnes in the prior month, General Administration of Customs data showed.

Exports during January-August rose 42% to 13.12 million tonnes.

China issued a third batch of VLSFO marine fuel export quotas earlier this month, bringing this year's total so far to 11 million tonnes. 

Customs data released on Friday showed that fuel oil imports under general trade rose further in August to 656,269 tonnes, their highest so far this year.

Some independent refiners were forced to resume purchasing the fuel as a feedstock for their plants because of tightening crude oil import quotas. 

Imports into bonded storage that include both high sulphur and low sulphur supplies also rose to the highest this year at 1.21 million tonnes, the data showed.

(Reporting by Chen Aizhu; Editing by Richard Pullin and Sherry Jacob-Phillips) ((aizhu.chen@thomsonreuters.com; +65 6870 3284; Reuters Messaging: aizhu.chen.reuters.com@reuters.net))