The Institute of Financial Accountants (IFA) has agreed terms to join with the Institute of Public Accountants Australia (IPA).
The merger will form the IPA Group from January 2015.
However, this is subject to more than 50% of IFA members voting in agreement at a special general meeting on 16 December.
According to the IFA, it has considered a number of options for amalgamation but settled on the IPA as its working relationship, established in 2003 and solidified in 2012, "represents the best option for growth".
"The IFA has also recognised that it has neither the financial resources, nor the infrastructure needed for extended growth," the IPA said in an FAQ section for members.
"Joining the IPA Group will deliver to the IFA the resources needed for the IFA to increase its global presence and recognition in the marketplace."
The IPA has 26,000 members and its headquarters are based in Melbourne. The move will create the world's largest SME focused accountancy organisation, the IFA said.
Branding and autonomy of each institute will be retained, the IFA assured its members, but its hoped that the merger will lead to a greater global reach, and establish economies of scale to cap costs and member fees.
IFA council chair Catherine Chamberlain said the IFA acknowledged it needs to secure 'stepped growth' in its membership numbers and enhancement of its current operation model.
"To help us achieve this long-held strategic goal, we need to join forces with a credible, like-minded, dynamic accountancy body that shares our vision to lead the profession globally and to have a lasting impact on the professional careers of our members long into the future."