The Financial Conduct Authority (FCA) and Prudential Regulation Authority (PRA) opened an investigation in 2017 looking at Mr Staley's alleged attempt to unmask an employee who wrote a letter raising concerns about the recruitment of a senior employee.
According to Barclays, regulators have found Mr Staley's actions represented a breach of individual conduct rules that relates to a "requirement to act with due skill, care and, diligence".
"Each have proposed that he pay a financial penalty", Barclays said.
"The FCA and PRA are not alleging that he acted with a lack of integrity or that he lacks fitness and propriety to continue to perform his role as Group Chief Executive Officer."
Mr Staley, who had asked the bank's security team to identify the author of the letter, can appeal the decision. He later apologised for his "mistake".
Barclays said it "continues to have unanimous confidence in Mr Staley" and will decide "what adjustment" to make to his pay once the FCA and PRA processes have been concluded.