ZURICH (Reuters) -UBS said on Wednesday it was examining the impact of the bankruptcy of First Brands on several of its investment funds, with the Swiss bank exposed to the tune of more than $500 million to the collapsed U.S. auto parts supplier.

Switzerland's biggest lender has exposure to First Brands debt and through supply chain finance agreements, spread across funds including at least one managed by its O'Connor hedge fund unit, according to court filings in the United States.

First Brands filed for bankruptcy protection last week after its lenders began investigating irregularities in the company's financial reporting. The company has $11.6 billion in total liabilities, according to the court documents.

Its collapse has unnerved debt investors and stoked fears of broader stress in corporate debt markets, and especially about growing risks in private credit where lending activity has soared in recent years.

U.S. bank Jefferies disclosed on Wednesday that it had a $715 million exposure to First Brands through a fund.

"This event affects many private credit and working capital providers across the industry," UBS said in a statement.

"In this highly fluid situation, we are working to determine the potential performance impact on the small number of our affected funds and are focused on protecting the interests of our clients."

While the economic fallout would be small for a bank of UBS's size, one analyst, asking not to be named, said the exposure was "not ideal for UBS's image and political perception" at a time when the lender was trying to persuade Swiss politicians to soften capital rules designed to make Swiss banking safer.