Chubb more than doubled its fourth-quarter net income to $US1.61 billion ($2.1 billion) as benefits flowed from the merger with Zurich-based Ace.

Net income for last year was up 45.9% to $US4.14 billion ($5.41 billion) compared with 2015.

“Chubb had a very good quarter that contributed to a year of great accomplishment in both financial and non-financial results,” Chairman and CEO Evan Greenberg said. “Operationally and culturally, our integration efforts are on track and we have either achieved or exceeded substantially all the financial and non-financial targets we set at the time of the merger.

“While market conditions globally are competitive, I expect as we progress through [this year] and the impact of the merger continues to fade and the power of the organisation gains more momentum, we will produce stronger growth.”

After-tax operating income in the December quarter was up 64.5% to $US1.28 billion ($1.67 billion), and net written premium improved 67.4% to $US6.94 billion ($9.06 billion).

The property and casualty (P&C) combined operating ratio for the quarter was 87.8%, a slight deterioration from 87.7% in the corresponding period of 2015.

P&C net written premium grew 76.1% to $US6.39 billion ($8.35 billion).

Ace finalised the acquisition of Chubb for $US28.3 billion ($36.98 billion) in January last year, creating the world’s largest publicly traded P&C insurer. The merged entity trades as Chubb.