(Reuters) - The S&P Dow Jones Indices said on Friday server maker Dell Technologies, data analytics firm Palantir Technologies (NYSE:PLTR) and property and casualty insurer Erie Indemnity will join the benchmark S&P 500 before the market opens on Sept. 23.
Shares of Palantir rose nearly 8% in extended trading, while those of Dell and Erie rose 6% and 3%, respectively.
The three companies will replace American Airlines (NASDAQ:AAL) Group, online marketplace Etsy (NASDAQ:ETSY) and diagnostics company Bio-Rad Laboratories in the index.
Shares of American Airlines were down 0.7%, while those of Bio-Rad Laboratories and Etsy fell about 1%.