LONDON—The amount of crude stored at the world’s largest oil-trading hub has hit a two-year high, according to data released on Monday, in another sign that the world has an oversupply of petroleum that won’t end soon.

Crude stocks reached 60.6 million barrels in June at a network of storage tanks in the Dutch ports of Amsterdam and Rotterdam and Belgium’s Antwerp, a hub known as ARA, according to Genscape. That is a record since the Louisville, Ky.-based information company started tracking ARA storage in 2013.

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