Accenture (ACN) will start trading on the S&P 500 next month, replacing Marshall & Ilsley (MI), which will retire from the index when the Bank of Montreal completes its takeover.

The move, effective at the close of trade on July 5, adds one of the worlds biggest standalone consulting companies to the index.

Shares of companies joining a major index such as Standard & Poors tend to rise as index-tracking funds start buying its stock. Accenture saw its shares climb 4.6% after hours Monday on the news.

Bank of Montreal (BMO) agreed in December to buy Marshall & Ilsley in a stock-for-stock deal valued at $4.1 billion.

S&P also said Amerigroup (AGP) will join the S&P Midcap 400 on July 1, replacing Nationwide Health Properties (NHP), which is being acquired by Ventas (VTR).

Northwest Bancshares (NWBI) will replace Amerigroup on the S&P Smallcap 600 on the same date.

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