The country's top refiner had planned to shut an about 80,000 bpd crude unit and some secondary units at its eastern India plant from Nov. 1, they said.
The refiner plans to shut a crude unit and a vacuum distillation unit for 40 days, a fluidised catalytic cracker for 50 days and a diesel hydro desulphuriser for 25 days, one of the sources said.
Haldia refinery has two crude and vacuum distillation units.
This source said the shutdown has been deferred to meet higher demand for gasoil and gasoline during the festival season.
The company did not immediately respond to a request for comment.
India's busy festival season begins this month, with several celebrations dotting the calendar until November, when the Hindu festival of lights, Diwali, celebrated by millions, takes place.
(Reporting by Nidhi Verma; Editing by Kirsten Donovan)