GRAM's shareholding in PanAust has moved from 24.1% to 55.6% after its sweetened its takeover offer for the copper and gold producer was recommended by the company's board on Friday last week.
The move above 50% triggers an automatic extension to the offer, with the deal now scheduled to close at 7pm (AEST) on May 27.
The revised $A1.2 billion offer announced last week offered PanAust shareholders $1.85 for every share in the company not already owned by GRAM.
It followed an initial offer of $1.71 per share by GRAM in March which was rejected by PanAust management, who labelled the offer opportunistic after a review by independent expert Ernst & Young found it to be neither fair nor reasonable.
At the time, EY assessed the fair value of PanAust shares to be in the range of $1.84-2.04.
GRAMS revised share offer represents a 51% premium to PanAust's closing share price prior to the announcement of the initial offer in late March.
While announcing the board's recommendation of the offer on Friday, PanAust chairman Garry Hounsell said the offer allowed shareholders to realise value for their shares and provided certain cash for the company.
PanAust operates the Phu Kham copper-gold operation and the Ban Houayxai gold-silver operation in Laos, as well as holding an 80% share in the Frieda River copper gold project in Papua New Guinea.