American International Group Inc. (AIG) headquarters seen on the day of the company's 2017 annual shareholder meeting at 175 Water Street, New York, U.S., June 28, 2017. REUTERS/Suzanne Barlyn

(Reuters) - American International Group Inc’s new global chief operating officer will receive an annual base salary of $1.25 million and a $15 million sign-on bonus, the largest U.S. commercial property and casualty insurer said in a filing on Thursday.

On Wednesday, AIG named Peter Zaffino, who until then headed Marsh & McLennan Cos Inc’s brokerage business, to work alongside new Chief Executive Officer Brian Duperreault.

AIG named Duperreault, 70, as CEO in May, selecting a protégé of former CEO Hank Greenberg and an industry veteran known for his turnaround expertise.

Duperreault was CEO of Marsh & McLennan from 2008 to 2012, and Zaffino, 50, said in a statement that he had worked closely with him there.

Zaffino will lead AIG’s daily operations in all countries, including Japan and Europe, as well as U.S. commercial field operations, AIG said.

The sign-on bonus, in exchange for compensation Zaffino would have received from Marsh, includes options to buy 1 million shares of AIG stock, which will vest subject to various terms during a seven-year period, according to the filing.

Zaffino is also eligible for short-term and long-term annual incentive bonuses, in addition to his $1.25 million base salary, AIG said.