Petroplus has been forced to shut down three refineries and to halve output at two others after lenders cut its credit lines. Analysts say a financing deal is required soon to allow the company to continue operating.
Industry sources said London-based BP was mulling financial support that would help safeguard its UK fuel supplies.
A company spokesman declined to comment on its future plans but said it was watching the situation closely.
Some dealers reported rumours that BP could take over Petroplus or some of its facilities but industry sources say this is unlikely as BP has been reducing its exposure to the refining business over the past decade.
(Reporting by Tom Bergin; Editing by Greg Mahlich)