"Five large banks reported improved second-quarter profits, fueled in large part by increases in net interest income as interest rates fell.</br></br>Profits at SunTrust Banks Inc., Wachovia Corp., First Fidelity Bancorp., KeyCorp and NBD Bancorp Inc. exceeded most analysts' estimates. The results continued what is proving to be a strong quarter for most regional banks. SunTrust, Wachovia, First Fidelity and KeyCorp also saw improvements in credit quality, while NBD saw a slight deterioration.</br></br>""Most banks are reporting higher net interest margins while keeping their expenses under control,"" said Richard Stillinger, a senior vice president of Keefe, Bruyette & Woods in New York.</br></br>In late trading on the New York Stock Exchange, SunTrust shares were quoted at $42.25, up $1.50; Wachovia at $64.50, down 50 cents; First Fidelity at $38.25, down 75 cents; KeyCorp at $34.50, down 25 cents; and NBD at $29.25, up 12.5 cents.</br></br>SunTrust"