BNY Mellon and State Street stand to benefit most as US regulators rush to ease a key leverage rule, giving the custody-banking giants room to once again accept deposits they’ve shunned in recent years. The Federal Reserve and the Office of the Comptroller of the Currency may unveil a proposal as early as next week to ease the leverage ratio from the 5 percent minimum currently in place for the nation’s eight largest banks, according to people with knowledge of the plan. BNY Mellon and State Street would see their minimum requirement drop to below 4 percent, giving the pair leeway to soak up billions of dollars in additional deposits, under draft terms described to Bloomberg.