Willis Towers Watson earned $US34 million ($44.47 million) net profit in the fourth quarter, taking its full-year net profit to $US312 million ($408.41 million).

This compares to a net profit of $US66 million ($86.4 million) for the corresponding quarter of 2015, calculated on a pro-forma basis, and full-year net profit of $US640 million ($837.78 million).

Broker Willis and professional services company Towers Watson completed an $US18 billion ($23.56 billion) merger in January last year.

Revenue in the December quarter totalled $US1.9 billion ($2.49 billion), giving $US7.9 billion ($10.34 billion) for the year.

Commissions and fees generated from the investment, risk and reinsurance segment fell to $US260 million ($340.3 million) in the fourth quarter from a pro-forma $US287 million ($375.66 million) in the corresponding period of 2015.

The fourth-quarter restructuring cost was $US78 million ($102.1 million) and integration expenses totalled $US60 million ($78.54 million).