** Energy World Corp EWC.AX surges as much as 257.1% to A$0.075, highest since May 16, 2022
** Stock last up 138.1%; set for best day on record
** Co enters subscription agreement with Energy World International and Slipform Engineering Group to convert all outstanding debt to shares
** Says estimated conversion amount of $440.5 mln at the time of completion would result in about 782.2 million shares being issued
** Appoints Edward McCartin as CEO and Alan Jowell as interim chair effective July 1
** About 14.6 mln shares traded - more than 11x of 30-day avg - in stock's busiest session since December 12, 2022
** YTD, EWC gains 127.3%
(Reporting by Keshav Singh Chundawat in Bengaluru)
((Keshav.SinghChundawat@thomsonreuters.com))