Oceana and Newmont announced the acquisition about five weeks ago, which included a due diligence period.
Oceana chief executive Mick Wilkes said in a statement on Saturday a ''definitive acquisition agreement'' had been made with with Newmont Mining Corporation.
Since the purchase announcement, Newmont decided it had to lay off 50 earthmoving contractors, following a slip in April which closed the road access into the historic Martha open pit. It could be up to year before it is safe enough to reopen.
Waihi now has about 290 staff and operates the underground Correnso mine. As at last December, there was an estimated 400,000 oz of gold reserves.
Oceana Gold will fund the purchase price from cash: of $US59.6 million as at March 31 and its recently increased revolving credit facility of $US225 million, of which it has drawn down $77.8 million. Oceana Gold will have the economic benefit of owning Waihi, effective from July 1.
