** Shares of Australia's TerraCom TER.AX slump as much as 23.3% to A$0.069, their steepest drop since March 1, 2021

** Coal miner says total sales volumes for the December quarter will be lower than 1.8 Mt in September quarter due to timing of rail access and vessel loading windows

** The co is also undertaking a partially underwritten renounceable entitlement offer to raise up to A$60 million ($40.21 million) to strengthen the balance sheet

** Around 8.5 mln shares change hands, nearly 1.6x 30-day average

** TER down 61.7% YTD

($1 = 1.4923 Australian dollars)

(Reporting by Keshav Singh Chundawat in Bengaluru)

((Keshav.singhchundawat@thomsonreuters.com))