** Shares of Westpac Banking Corp WBC.AX fall as much as 3.9% to A$37.80 in worst intraday session since April 14
** Stock among top losers on the benchmark S&P/ASX 200 index .AXJO
** Top loser on the financial sub-index .AXFJ, which is down 1.6%
** Australia's second-largest mortgage lender trades ex-dividend; to pay interim dividend of 77 Australian cents per share
** YTD, stock down 1.9%, including the day's moves
(Reporting by Shivangi Lahiri in Bengaluru)
((shivangi.lahiri@thomsonreuters.com))