formaldehyde-free fixing agent factory Buying by state-owned refiners pushed up China's crude oil imports in May 15.4% year on year to 37.2 million mt, or 8.8 million b/d, but analysts said they expected crude inflows to ease in June due to high stocks.

Imports in May rose 4.7% month on month, preliminary data released Thursday by the General Administration of Customs showed.

The imports are the second highest level ever after 9.21 million b/d imported in March this year.

"The increase was mainly from state-owned refiners as crude arrivals for independent refiners declined from April," said Hou Rui, an analyst with S&P Global Platts' China Oil Analytics.

rubber expo 2018 Independent refineries in China's eastern Shandong and Hebei provinces imported 8.43 million mt, or 1.99 million b/d, of crude oil in May, down 3% from April despite a 46% year-on-year increase, Platts data showed.

He added that most of the cargoes for the state-owned refiners were booked in March when oil prices were low.

The monthly average Platts Dated Brent and Platts Dubai crude assessments were $51.56/b and $51.20/b respectively in March, a four-month low.

"Refinery outages remained high in May, so the incremental barrels are likely to flow into storage for use in June," Hou said.

Platts China Oil Analytics estimated that around 1.31 million b/d of refining capacity was shut in May for maintenance -- 728,000 b/d for Sinopec refineries and 285,000 b/d for PetroChina refineries. This was down from 1.5 million b/d in April, but still higher than last year.

Preliminary production data for May, including refinery runs, is scheduled to be released around June 14 by the National Bureau of Statistics.