Contact: James G. Barone 724-465-1417 TO BE RELEASED: 9:00 a.m., Tuesday, September 22, 1998 S&T Bancorp Declares Quarterly Dividend and Stock Split Indiana, Pennsylvania (Nasdaq NMS:STBA) - S&T Bancorp announced that its Board of Directors declared a $0.33 quarterly cash dividend at yesterday's meeting. The cash dividend is payable on October 23, 1998 to shareholders of record October 1, 1998. In addition, the Board of Directors declared a 2 for 1 stock split which will be effected in the form of a 100 percent stock dividend. The new shares will be distributed on October 30, 1998 to shareholders of record October 15, 1998. The split will increase the number of shares outstanding to approximately 27,500,000. Headquartered in Indiana, PA, S&T Bank, the principal subsidiary of S&T Bancorp, Inc. operates 37 offices within Allegheny, Armstrong, Clearfield, Indiana, Jefferson and Westmoreland counties. With assets of approximately $2 billion, S&T Bancorp stock trades on the Nasdaq National Market System under the symbol STBA.