** Shares of custodian bank State Street STT.N fall 3.5% to $109.03, hitting their lowest level since July 17
** Stock ranks among Friday's worst performers on the S&P 500 index
** Co reports Q3 net interest income of $715 million, falling short of Wall Street estimates of $735 million, according to data compiled by LSEG
** STT's expenses rise 5.5% to $2.43 billion in the quarter, representing an 11.7% increase from the year-ago period
** However, co's profit and revenue for Q3 beat estimates
** 13 of 17 brokerages rate the stock "buy" or higher, 3 "hold" and 1 "sell"; their median PT is $130 - data compiled by LSEG
** Including session's moves, stock is up 11.4% YTD compared with a 7.6% increase in the S&P 500 financials index .SPSY
(Reporting by Ragini Mathur in Bengaluru)
((Ragini.Mathur@thomsonreuters.com;))