Saudi Arabia's crude oil shipments to its biggest customer, China, are expected to drop to their lowest level in more than a year in April, trade sources said on Thursday, partly due to maintenance programmes at Chinese refineries owned by Sinopec.

The OPEC producer allocated 34 million barrels of Saudi oil in April to its Chinese customers, down from 41 million barrels in the previous month, Reuters data showed.

The drop in China's demand for Saudi oil comes despite the Organization of the Petroleum Exporting Countries and their allies, a group known as OPEC+, agreeing to proceed with their plan to raise production in April.

Sinopec plans to shut at least 700,000 barrels per day (bpd) of crude processing capacity from mid-March through May at subsidiaries including the Yangzi, Jiujiang and Gaoqiao refineries, according to data compiled by Reuters based on industry and trade sources.

Saudi Aramco and Sinopec did not immediately respond to requests for comments.

Crude oil markets in Asia are also stabilising after U.S. sanctions on Russia and Iranian oil disrupted trade in late 2024 and early 2025.

China's imports of Russian Far East crude and Iranian oil are set to rebound in March as non-sanctioned tankers, drawn by lucrative payoffs, joined the trade replacing vessels under U.S. embargo, trade sources and analysts said.

Russian oil supplies to India, the world's third largest oil importer, have also recovered this month.

(Reporting by Florence Tan, Trixie Yap and Chen Aizhu Editing by Tomasz Janowski and Philippa Fletcher)