NZOG acquired a 19.99% share in the junior in December from Cue's partner in the Maari field, Todd Energy, for $13.96 million, raising questions over its ultimate intentions.
Last month, Cue Energy chairman Geoffrey King issued a letter to shareholders advising them that he had met with NZOG chairman Peter Griffiths but was still unsure of NZOG's intentions.
NZOG has now revealed, unsurprisingly, that it is after Cue primarily for its 5% interest in the producing Maari oilfield, which the company sees as a quality asset that will fit its portfolio well.
NZOG stated that it would be comfortable with at least a further 10% holding in the company at the end of the offer period, though its offer extends to 100% of shares it doesn't yet hold.
The takeover offer values Cue at around $69.8 million.
Cue has advised its shareholders to ignore the offer, saying it undervalues the company and that it is "substantially below the premium typically paid in Australian control transactions".
In addition, Cue said that the offer had been made in poor market conditions which led to material reductions in the value of a lot of companies.
Cue said it expected to release its full target statement on the takeover offer by February 26.