NEW YORK (AP) ¿ Shares of industrial equipment maker Roper Industries Inc. rose Wednesday after Standard & Poor's said it will add the company to the S&P 500 index next week.

Roper shares were up $1.74, or 3.3 percent, to $55.02 in afternoon trading.

Stocks often rise after they are added to major indices because they are bought up by managers of investment funds that track those benchmarks.

On Dec. 22, Sarasota, Fla.-based Roper will be added to the index, replacing Ensco International Inc., which was removed because the oil driller is moving its headquarters to the United Kingdom.

Roper is currently part of the S&P MidCap 400.

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