Western Union (WUWI) will replace Andrew Corp.( ANDW) in the S&P 500 index following the close of trading on Friday.

Western Union is being spun off by S&P 500 constituent

First Data

(FDC) - Get Report

in a deal expected to close on or about that date.

Andrew Corp. will replace

Cabot Microelectronics

(CCMP) - Get Report

in the S&P MidCap 400, and Cabot will replace

Bally Total Fitness

( BFT) in the S&P SmallCap 600.

At Monday's close, Bally Total Fitness had a market capitalization of roughly $77 million; the minimum market cap required to maintain a listing in the S&P SmallCap 600 index is $300 million.