Filled oil drums are seen at Royal Dutch Shell Plc's lubricants blending plant in the town of Torzhok, north-west of Tver, November 7, 2014. REUTERS/Sergei Karpukhin/File Photo

LONDON (Reuters) - Royal Dutch Shell said on Thursday that crude trading boosted its fourth quarter profits to a four-year high even as oil prices collapsed.

Benchmark Brent oil prices collapsed from a four-year high of $86 in early October to a low of $50 a barrel within weeks.

Shell is the world’s largest oil trader, buying an selling over 10 million barrels a day. The trading operations often help oil producers offset large swings in oil prices and in some cases can generate large profits.

Shell said that its trading operations in the previous three quarters were weak. For the year, trading of refined products such as gasoline and diesel was weaker in 2018 compared to the previous year, while crude oil trading was stronger and liquefied natural gas (LNG) trading gave a further boost, Shell said in its results.

The trading results, which the company did not disclose in detail, were boosted by the Anglo-Dutch firm’s positions in Oman and Brazil, two of its large oil production hubs, Chief Financial Officer Jessica Uhl said.