Shares of Keystone Financial Corp. rose 4.7% Tuesday after Standard & Poor's Corp. announced the banking company would join the S&P MidCap 400 index after the close of trading Nov. 19.

Keystone, a $6.9 billion-asset company based in Harrisburg, Pa., will replace Firstar Corp., whose proposed merger with Star Banc Corp. is expected to close Thursday. S&P said Firstar, as the combined company would be called, would not appear on another index "at this time."

Previously Keystone had been on the S&P SmallCap 600 index. Its shares rose after the announcement because investment funds that seek to replicate the performance of S&P's indexes bought the stock. Trading volume in Keystone shares Tuesday was five and a half times above daily average. It closed up $1.375, to $30.75.

News that Firstar would not appear on an S&P index dampened enthusiasm for its stock, which fell Tuesday $2.375, to $56.8125. Star Banc shares dropped $2.625, to $75.50.

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