By Josh Beckerman 
 

Real-estate investment trust Realty Income Corp. will replace telecommunications company Windstream Holdings Inc. in the S&P 500 after the close of trading April 6.

S&P Dow Jones Indices said Windstream will join the S&P MidCap 400. It said Windstream's pending spinoff of some network assets into an independent, publicly traded real-estate investment trust will make the company "more representative of the mid-cap market space." Windstream said in July that the move would help it accelerate network investments and significantly reduce debt.

Inclusion in the S&P 500 is typically a boon for a stock as index-tracking funds that follow the S&P 500 will need to buy its shares at that time.

In after-hours trading, Realty Income rose 2.6% to $52.38, while Windstream was down two cents to $7.42.

Another REIT, Douglas Emmett Inc., will replace Realty Income in the MidCap 400.

Casino-equipment company International Game Technology is also leaving the MidCap 400 due to its pending acquisition by Italian lottery company Gtech SpA.

Write to Josh Beckerman at josh.beckerman@wsj.com

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