China's gasoline exports in October more than doubled from a year ago to a record as refiners' increasing processing runs created a fuel surplus in the domestic market, spurring overseas sales.

Gasoline shipments were 1.73 million tonnes last month, data from the General Administration of Customs showed on Saturday. That compares to 1.67 million tonnes in September and 650,000 tonnes in October 2018.

Diesel exports fell to 1.19 million tonnes from 1.48 million tonnes in September.

"Fuel demand would be under pressure in the domestic market amid a slowing economy. Meanwhile, crude throughput is expected to stay at a relatively high level in the coming months, which would encourage refineries to seek buyers from other markets," said Wang Zhao, an analyst at China Sublime Information, ahead of the data release.

China's crude runs rose to 13.62 million barrels per day (bpd) in October, just below the record of 13.75 million bpd in September, as new large-scale refiners ramped up their operations.

Jet kerosene shipments were 1.58 million tonnes last month, up from 1.5 million tonnes in September and 1.19 million tonnes last year.