UPDATE 1-China's top refinery Zhenhai plans crude units' overhaul in March, May - sources

(Adds construction of new hydrocracker)

SINGAPORE, March 4 (Reuters) - Sinopec Corp’s largest refining subsidiary, Zhenhai Refining and Chemical Company, is expected to shut down a 160,000 barrels per day (bpd) crude distillation unit around mid-March for regular maintenance lasting about 40 days, three industry sources told Reuters.

The refinery, based in east China’s coastal city of Zhenhai, also plans to shut another crude unit of 180,000 bpd capacity around mid-May for regular overhaul for a similar period, two of the sources said.

They said the refinery, China’s single largest by far with a total processing capacity of 460,000 bpd, also started last week building a 4 million tonnes per year hydrocracking unit.

The sources declined be named as they are not authorized to speak to the media.

Sinopec declined to comment.

The new hydrocracker will allow Sinopec to manufacture bigger quantities of higher quality transportation fuels such as jet fuel and diesel as well as low-sulphur shipping fuel.

Demand for cleaner marine fuels is set on the rise due to new global emission rules that started this year and that cap the sulphur content of shipping bunker fuels at 0.5% versus previous 3.5%.

Zhenhai, also one of Sinopec’s largest exporters of refined fuel, operates a third crude unit of 120,000 bpd. (Reporting by Chen Aizhu in Singapore; Additional reporting by Muyu Xu in Beijing; Editing by Shri Navaratnam and Maju Samuel)