GM Replaces Heinz in S&P 100

General Motors Co. (GM), the largest U.S. auto maker, will replace ketchup manufacturer H. J. Heinz Co. (HNZ) in the S&P 100 and 500 indices, while insurer American International Group Inc. (AIG) will join the S&P 100.

The changes are scheduled to occur after the close of trading Thursday.

Shares of GM rose 3.5% to $35.64 after hours. The shares of companies joining the S&P 500 often rise because many portfolio managers try to track the index. To do that, they must buy shares of the companies that become part of the index.

GM will replace Heinz, which said Monday that it has that it has received regulatory approval to be acquired by an investment consortium comprised of Berkshire Hathaway Inc. (BRKA, BRKB) and an investment fund affiliated with 3G Capital. The merger agreement between the parties was announced Feb. 14 and the deal is expected to close on or about Friday.

AIG will replace Baker Hughes Inc. (BHI) in the S&P 100. The oilfield-services company, which will remain in the S&P 500, now has a total market capitalization of less than $21 billion and is no longer representative of the mega-cap market space.

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