Cendant ( CD) is being removed from the S&P 500, while two businesses it's spinning off are joining the index. Standard & Poor's said Monday that lodging concern Wyndham Worldwide will replace its soon-to-be-former parent in the S&P 500. Another pending Cendant spinoff, real-estate brokerage franchiser Realogy, will be added to the S&P 500 by claiming the spot currently held by computer maker Gateway ( GTW). The changes will be official after the close of trading July 31. Gateway's market capitalization of roughly $670 million ranks the company 500th in the index. Wyndham is set to trade on the New York Stock Exchange under the symbol WYN, and Realogy will have the ticker H. Cendant will replace Credence Systems ( CMOS) in the S&P MidCap 400. Credence, with a market cap of roughly $290 million, is ranked last in the index. Also, PS Business Parks ( PSB) is set to succeed Diagnostic Products ( DP) in the S&P SmallCap 600, and Keystone Automotive Industries ( KEYS) has been chosen to take the spot held by Russell ( RML) in the same index. Both Diagnostic Products and Russell are being acquired.