NEW YORK (Reuters) - American International Group Inc. is expected to name former Prudential Plc chief executive Mark Tucker as head of AIA, as it prepares the Asian life insurance unit for an initial public offering, a source familiar with the matter said yesterday.

Tucker will replace AIA chief executive Mark Wilson, the source said, adding that an announcement was expected as soon as today.

Wilson is expected to remain at the unit until the end of the year, the source said.

The move is the latest sign that AIG CEO Robert Benmosche is asserting his authority at the bailed out insurer, which is nearly 80 percent-owned by the US government.

Last week, Harvey Golub stepped down as AIG's chairman, at odds with Benmosche over the unsuccessful sale of AIA to Prudential for $35.5 billion. AIG named Steve Miller as its new chairman.

AIG decided last week to revive plans for an IPO of AIA, expected to be the biggest ever done solely in Hong Kong. Bankers said the IPO, which could be completed by year-end, is targeting around $15 billion in proceeds.

Benmosche had supported a sale of the business to Prudential, instead of an IPO, and wanted to do a deal even at a lower price when the transaction ran into trouble. But he was overruled by AIG's board, which lost confidence in the ability of Prudential CEO Tidjane Thiam to close the deal.