BY VICTORIA MCGRANE

WASHINGTON—The largest U.S. financial firms continue to feel the squeeze from the Dodd-Frank financial-overhaul law as regulators on Monday moved forward with two new rules, both of which single out large firms for tougher treatment.

The Federal Deposit Insurance Corp.'s five-member board unanimously approved a draft rule, written jointly with six other regulators, that would require large financial firms to hold on to at least half of top executives' bonuses for three years or longer. The aim is to tie the final payments to the outcomes of the employees' trades and other decisions over time.

The deferral requirement, if approved, ...