The company is issuing 66.6mln new shares, priced at 3p per share.
Proceeds from the Ortac placing will fund the proposed acquisition of a US$2mln convertible loan note issued by Casa Mining Limited.
New and existing investors, and a number of Ortac directors all participated in the Ortac share placing.
Gold exploration in the DRC
The Casa Mining venture is focussed on gold exploration in the Democratic Republic of Congo (DRC).
CASA owns 71.25% of the Misisi gold project in South Kivu, eastern DRC, around 350km south of Bukavu and 180km north of Kalemie and that includes the Akyanga deposit along with the Lubitchako, Tulongwe, Kilombwe and Mutshobwe targets.
Ortac steadily building up Casa stake
"Ortac has steadily been building up its stake in Casa, where this significant and new investment, following conversion, would make Ortac, Casa's largest shareholder with an approximate 45% stake in the company,” said Vassilios Carellas, Ortac chief executive.
“I am delighted with the support we received for this Placing from both existing and new shareholders, which is testament to the improving market sentiment we are now seeing across the metal and mineral exploration sector.
“With this funding in place, Casa will commence a new drill programme on their flagship Akyanga deposit where a revised geological model is in place and where this new drilling will help Casa work towards unlocking, what is potentially a significant gold resource in excess of 2mln ounces."