Metropolitan Water Reclamation District of Greater Chicago terminated ING Investment Management, which ran a $34 million enhanced S&P 500 index portfolio, because of performance, said George Kirie, senior financial analyst. The $1.1 billion pension fund moved the money to an existing S&P 500 index fund run by Northern Trust, increasing it to $90 million, Mr. Kirie said. Plan officials will probably not look for a new enhanced index manager, he said. Standard Valuations assisted. Phil Margolis, ING spokesman, declined to comment.