** Cross-border payments processor CAB Payments' CABP.L shares fall as much as 22% to 83.20p, their lowest since Aug. 5 ** The London's listed-company's U.S. rival Stonex Group SNEX.O pulls out of takeover talks
** CABP says it would drive "attractive, sustainable growth" from 2025
** Stock top pct loser on FTSE Small Cap .FTSC index
** Currently stock down 17.3%, taking YTD gains to ~6%
(Reporting by Megha Kumari in Bengaluru)
((megha.kumari@thomsonreuters.com))