Pret A Manger has replaced its auditor KPMG with EY, an indication that the chain could be going ahead with a US float.
KPMG resigned as auditor this week because the company’s work did not comply with Security & Exchange Commission (SEC) rules.
The SEC, which largely regulates companies that have a listing on US stock markets rather than privately owned firms, stipulates that auditors are not allowed to carry out financial projects in addition to audit work.
A spokeswoman for Pret A Manger told The Sunday Telegraph: "After nearly 10 years of audit services from KPMG, we have decided to rotate audit firms in line with best practice and have appointed EY."
In May it was rumoured that Bridgepoint, which owns a controlling stake in Pret A Manger, had enlisted JP Morgan and Jefferies to lead a flotation in New York.
A spokesman for Bridgepoint told City A.M.: "As a committed shareholder in Pret we are always exploring appropriate opportunities to ensure the future growth of the company. If such opportunities materialise, we will update the market."
It is understood that Bridgepoint would only want to sell down its stake rather than sell its entire holding.
In April, the healthy eating chain posted figures showing that sales had risen 15 per cent to £776.2m in the year to the end of December, up from £677.1m in 2015.
Pret A Manger was not immediately available for comment.