Republican-led tax cuts helped Citibank top Wall Street's profit projections for the three months through September, even as revenue flattened.

Earnings of $1.73 a share compared with the $1.69 average estimate from analysts, and net income rose to $4.6 billion as the New York-based lender's effective tax rate dropped 7 points to 24 percent. Revenue of $18.4 billion was little changed from the year before, and lower than analysts expected.

Chief Executive Officer Michael Corbat said the bank is "firmly on track to deliver on our full-year 2018 financial targets."

Overall revenue at Citi's markets and securities business dropped 5 percent to $4.5 billion, while investment banking fees dropped 8 percent to $1.2 billion.