Shares of U.S. banks dropped in premarket trading after a Fitch Ratings analyst told CNBC that the agency could downgrade several lenders, while a proposed rule change by a top banking regulator added to investor worries.

Big banks JPMorgan Chase, Wells Fargo and Bank of America fell between 1.5% and 1.6%.

Among the mid-sized lenders, Western Alliance Bancorp, Zions Bancorp and PacWest Bancorp fell between 2% and 5%.

(Reporting by Niket Nishant in Bengaluru; Editing by Arun Koyyur)