Overnight Toronto-listed Mitra confirmed that three of its major shareholders will put in almost $40 million, with a small portion being injected by the some of the company's directors and management.
The deal replaced an earlier brokered private placement.
In addition, Mitra has entered into a $28 million convertible debt facility with Tyrus Capital Event that can be drawn down in $5 million tranches.
The facility will have an interest rate of 7.5% payable quarterly in cash. Fees of 3% will also be payable.
The funds drawn down under the facility will be used to fund future mergers and acquisitions other than the Stag purchase, and there are market rumours that Mitra is looking to snap up assets in Australia and around Southeast Asia, in addition to its proposed Vietnamese investment.
"We're delighted with the very strong support provided by our major shareholders, which, with the private placement and the facility, raises approximately 35% more capital than the company's initial target of $50 million," executive chairman Paul Blakeley said.
"This puts Mitra in a strong financial position to complete the Stag acquisition and carry out additional infill development drilling on the field.
"We now have the financial flexibility to accelerate our growth trajectory, taking advantage of the increasing number of acquisition opportunities we see in the region, to deliver additional value to our shareholders, and become a significant oil and gas producer in Asia Pacific."
The Stag deal is now expected to complete by November 15, and since the acquisition is back-dated to July 1 the company expects to see a positive cash adjustment in its favour, reducing the gross $10 million the company had been expected to pay Santos and Quadrant Energy.
While early valuations on Stag were $100 million, the field was initially sold for $50 million to Malaysia's Sona Petroleum, later reduced to $25 million, however Sona shareholders balked at that prices and Mitra swooped in with its offer.
The deal terms also include potential contingent payments of up to $15 million, based on planned expansion plans and improvements in the oil price.
Once the sale closes it expects to have $20 million in free cash, plus its facility.
The 20-year-old Stag has an estimated 10.1 million barrels remaining with probable reserves of 14.6MMbbl, and is producing around 3750bopd from 10 wells. Stag has 3P upside of 18.6MMbbl.
Mitra has identified cost reduction measures to continue to lower operating costs and it is planning to drill up to eight wells over the next two years: one appraisal pilot and three infill producers in the Stag West area in 2017 and up to three further wells in the Stag East area in 2018.
The oiler expects 2017 production from the field to average around 4323boepd, rising to 5394boepd in 2018 before falling to 4824boepd in 2019.
Mitra will also consider appraisal activities in the undrilled low risk exploration area of Hart and Stag South.
Tyrus chief investment officer Tony Chedraoui said his company saw a unique time to consolidate producing and free cash flowing assets at deep value from motivated sellers in the Asia Pacific region.
"In the space of less than four months since joining the company in June, Paul and his team have secured two compelling transactions and are now closing the first transaction, which demonstrates the team's strong M&A ability and confirms its operating track record and credibility with market participants," Chedraoui said.
"With the pending closing of the Stag acquisition and this upsized financing, Mitra is uniquely positioned to capture this opportunity and add further upside through future value-enhancing acquisitions to be sourced by the team and to accelerate its transformation into a regional champion."
The facility will mature after three years, at which time Tyrus will have the option to convert the full amount of any principal owing into shares, although it has the option to convert any principal owing under the Facility at any time prior to maturity.
