"The availability could be because of supply resumption after the end of a turnaround at one of the company's Paradip refinery in mid- to second half September," one of the sources said.
The tender to sell up to 16,460 tonnes of diesel loading from Paradip will close on Nov. 11, with bids to remain valid until the close of the same day.
The company had earlier sought diesel for June arrival in the spot market, another source said.
Indian Oil could not be immediately reached for a comment.
(Reporting by Trixie Yap; Editing by Vinay Dwivedi)