UPDATE 2-Chief executive of AIG expected to step down-WSJ

(Adds detail on possibilities for CEO successor, background)

NEW YORK, June 15 (Reuters) - The board of American International Group Inc (AIG.N: Quote, Profile, Research, Stock Buzz) was meeting on Sunday to accept the possible resignation of Chief Executive Officer Martin Sullivan, The Wall Street Journal reported on its Web site, citing a person familiar with the matter.

The Journal story said the resignation was not a "done deal" but was considered "highly likely."

AIG spokesman Michael Arcaro declined to comment on the report.

In recent weeks, several large shareholders have been pushing for Sullivan's ouster after the giant insurer posted back-to-back quarters of record losses, stemming from about $20 billion in write-downs in the market value of assets linked to subprime mortgages.

To date, the board has expressed its support for Sullivan, who was named CEO about three years ago.

Former director Eli Broad and fund managers Shelby Davis of Davis Selected Advisers LP and Bill Miller of Legg Mason Inc (LM.N: Quote, Profile, Research, Stock Buzz) wrote in a letter obtained by Reuters last week that "significant and immediate changes at both the management and board level are clearly called for."

The same group sent another letter to the board last month, also expressing concern over Sullivan's management.

Separately, former AIG CEO Maurice "Hank" Greenberg, who remains a large shareholder, has also been critical of management and AIG's board.