ABM secured commitments for a A$6 million private placement at 10c per share, a 26.6% premium to ABM's last closing price of 7.9c.
St Barbara will chip in $4.4 million, giving the miner around 10% of ABM.
The company already holds 16% stakes in Victorian gold explorer Catalyst Metals and Cobar Basin explorer Peel Mining.
St Barbara joins fellow mid-tier Independence Group as a substantial shareholder in ABM.
IGO holds around 9% currently and is in a joint venture with ABM at Lake Mackay.
"Having two successful exploration and mining companies, such as St Barbara and IGO, support ABM is a clear confirmation of the quality of ABM's exploration team, strategy and portfolio of high-quality gold and base metal projects," ABM managing director Matt B...