The ASX released a consultation paper regarding the changes back in May, with the new rules to come into effect on December 19.

However, it softened its stance on several changes, with the net tangible assets test increased to $A4 million from $3 million, down from the proposed lift to $5 million.

The market capitalisation test has been increased to $15 million from $10 million, down from the proposed $20 million.

The ASX will implement a new 20% minimum free float requirement and will require a company to have at least 300 shareholders holding at least $2000 worth of shares each.

New listings will have to provide at least two full financial years of audited accounts, down from a proposed three years of records.

Research by S&P Global Market Intelligence in June showed that 212 listed junior miners – or around a third of listed miners – would not be admitted to the list if subjected to the new thresholds.

Law firm Gilbert + Tobin warned at the time that there was likely to be a “significant decline” in the number of junior mining IPOs and backdoor listings.

It comes just as the market for mining IPOs has started to pick up.

The Association of Mining and Exploration Companies CEO Simon Bennison said the ASX had attempted to find a balance.

“The ASX was faced with an objective to ensure that the market meets the principles of quality and integrity, and remains internationally competitive; whilst not creating additional and unnecessary barriers to the listing process which dampen investment in an extremely competitive market place,” he said.

“It remains to be seen whether this objective has been met.”

While AMEC was pleased with some of the compromises, it was still concerned over a number of the changes.

“In view of the economic conditions prevailing in the mineral exploration sector, AMEC had recommended that it be treated separately and ‘carved’ out of any changes to the ASX Listing Rules,” Bennison said.

“Unfortunately, that has not occurred.”

AMEC said it would monitor the impact of the new rules and would hold a special information session for members.

Law firm Steinepreis Paganin will also hold a briefing for miners in Perth next Thursday.