(Adds details of delay, context, RBA and ASIC statements, and background)

Aug 3 (Reuters) - The Australian Securities Exchange said on Wednesday it would delay an overhaul of its main share trading software by up to 20 months, citing problems achieving "scalability and resilience".

The delay until late-2024, among several, takes it to nearly a decade of ASX Ltd's project to modernise its equities clearance software Clearing House Electronic Subregister System (CHESS).

The CHESS software enables ASX's registry to manage settlement of transactions, and the exchange has strived since 2017 to replace with blockchain technology in a bid to cut costs for customers.

ASX, which has been battling with several software glitches, said it will engage Accenture to provide an independent review of the new CHESS application.

The bourse operator and its application software provider, Digital Asset, realised that the application required more work than anticipated.

In a joint statement, the Reserve Bank of Australia Governor Philip Lowe and the Australian Securities and Investments Commission (ASIC) Chair Joseph Longo expressed their disappointment on the further delay.

The review initiated by ASX was an "important step in providing assurance that the new CHESS application software will be fit for purpose," Lowe added.

"It is critical that Accenture now undertake this review to provide assurance on the delivery of a resilient replacement for CHESS and a high degree of confidence in a revised go-live date," Longo said.

(Reporting by Indranil Sarkar in Bengaluru; Editing by Sherry Jacob-Phillips)