** Community bank Winchester Bancorp's WSBK.O shares fall 6.5% to $9.35 in Nasdaq debut

** Stock opened for trading at $10.1 vs $10 offer price

** WSBK sold ~4 million shares in its initial public offering in connection with its mutual bank conversion

** Mutual-to-stock conversion occurs when financial institutions, such as banks or savings associations, convert from mutual to stock form

** Mutual banks are owned by their depositors unlike traditional banks that are owned by shareholders

** Such conversions can be attractive as depositors get first crack at any stock offering at discounted price

** Established by Massachusetts Legislature in 1871, WSBK has four branch offices located in Arlington, Danvers and Woburn

** WSBK has 9.3 million outstanding shares after mutual bank conversion

** Raymond James was marketing agent for stock offering

(Reporting by Arasu Kannagi Basil in Bengaluru)

((ArasuKannagi.Basil@thomsonreuters.com;))