Porsche has had its application for a 1.75 billion Euro (£1.5 billion) loan rejected by German state-controlled bank KFW.
Porsche has a nine billion Euro (£7.7 billion) debt mountain which it acquired in the course of a failed takeover attempt of Volkswagen.
After failing to secure a 1.75 billion euro (£1.5bn) loan from commercial banks, Porsche turned to KFW and submitted an application for an extraordinary loan.
Porsche said on Tuesday that KFW had rejected the loan application, adding it would not make another request for a loan with the bank.
Porsche is reported to be in talks to sell part of its VW stake to Qatar, and is under pressure to merge with VW.