In an update this morning the copper miner said it expected to resume trading on Monday, with a number of spectators tipping a deal to eventually be sealed.
The speculation comes after GRAM made a $A1.71 per share unconditional offer at the end of March.
PanAust formally rejected the offer, saying it had been opportunistically lobbed at a low point for its share price and commodity prices.
Taking stock of the latest developments, GMP Securities said yesterday it appeared many of PanAust's larger shareholders were holding out for a higher offer.
The initial GRAM offer closes on May 15.
"It's expected that if GRAM declares the offer final, the larger institutional holders will sell and give GRAM a majority holding, although not the 90% required," GMP said.
"Time is running out for PanAust management to negotiate better terms for its shareholders. But it appears GRAM will walk away the definitive victor of the well-timed bid."
Earlier this week Macquarie lifted its target price for PanAust from $1.71 to $1.80 in anticipation of a higher offer from GRAM.
"GRAM currently owns 24% of PanAust and we believe that a small lift in the offer price to $1.80 could be sufficient to get the deal done," analysts said.
PanAust shares were in a trading halt at $1.73 this morning.