"As a precautionary safety measure, the Manali Refinery of CPCL was shutdown effective night of December two and the Cauvery Basin Refinery at Nagapattinam was shutdown effective night of December 6, 2015," city-based company said in a BSE filing.
The company said it was unable to inform the stock exchanges due to "non-availability of communication system and water logging in the office and the abnormal situation arising out of natural calamity".
Shares of the company ended at Rs 201.15 apiece in BSE.