NEW DELHI- India's Nayara Energy will cut crude processing by about 90% during a three-week maintenance shutdown of a 360,000 barrel-per-day (bpd) crude unit at its Vadinar refinery in western Gujarat state from early October, two sources said.

Nayara, part-owned by Russian oil major Rosneft ROSN.MM , will also shut some secondary units for a catalyst change from Oct. 1, one of the sources said. A second source however said there could be a delay of few days.

The sources said the second 40,000 bpd crude unit will continue to operate during the October turnaround of the key units.

Nayara did not respond to Reuters' request for comments.

(Reporting by Nidhi Verma; Editing by Jan Harvey, Kirsten Donovan) ((nidhi.verma@thomsonreuters.com; +91 11 49548031; Reuters Messaging: nidhi.verma.thomsonreuters.com@reuters.net))