China’s largest state-run banks lowered interest rates on deposits, reflecting a growing concern that the economy has not rebounded as strongly as expected.

The major restructuring, a possible precursor to future I.P.O.s, was announced after Jack Ma, its founder, returned to mainland China after a yearlong absence.

Bao Fan, a well-connected banker, is the latest businessman in China to disappear, raising concerns that Beijing’s crackdown on the technology and financial industries will...