Jaguar Land Rover owner Tata has pledged shares worth at least £1.4 billion to secure loans, raising concerns over the company's financial health.
Tata Sons, the group holding company, has filed documents with the Bombay stock exchange which show it has committed a 29% stake in Tata Motors against the loans.
However it runs the risk of losing the shares should it default.
Analysts claim the move is unsettling as companies do not usually pledge shares to raise working capital unless other means of funding are unavailable.
The company fuelled fears over its access to credit this month by failing to give a firm update on the refinancing of a $2 billion (£1.4 billion) bridging loan and revealed its first quarterly loss in seven years.