The negotiations are heating up to make a catch-weight showdown between Australian rivals Anthony Mundine and Jeff Horn.

Earlier this month, Horn suffered his first career defeat when he was dominated and stopped by Terence Crawford at the MGM Grand in Las Vegas on June 10. In losing, Horn lost his WBO welterweight title.

Local experts are estimating that both boxers could walk away with $4 million each with a 50-50 deal based on the domestic revenue and pay-per-view profits.

Mundine, who captured world titles at much higher weights like super middleweight, would still be a very live dog to win at his advanced age.

“We’re coming up to seal a deal,’’ said Mundine’s advisor Emaid Dib.

“Anthony is approaching the bout like it will be the fight of his life. He is very determined to put on the best performance of his career. He knows Jeff is a great fighter but his whole life has been about taking on big challenges in rugby league and boxing.’’

After losing to Crawford, Horn brushed aside the idea of facing Mundine - but now he's changed his mind when reviewing the financials involved.

“I’m up for the Mundine challenge,’’ said Horn.

“He was the big star when I was just a young amateur starting out so it would be exciting to face him in front of a big crowd. We sparred once five years ago and I did pretty well so let’s see what happens in a real fight.’’

And Horn’s trainer, Glenn Rushton, is also on board with this contest taking place in the fall.

 “Anthony is the perfect fight for Jeff coming back,’’ Rushton said.

"I think the fight is big enough to be held at Suncorp Stadium. Dean Lonergan, Jeff’s promoter, has presented us with a list of possible opponents and there is the possibility of a rematch with Manny Pacquiao at some stage but I think for now the Mundine fight could be huge and I’m sure that thousands of Mundine fans would come up from NSW to watch.

“It could be very good for tourism in Queensland at a time when there won’t be too many other big sporting events in Brisbane. We haven’t agreed to anything yet but I like the idea of the fight. I can assure you we will not be underestimating Anthony. Even at 43 he is still a dangerous fighter and Jeff will be ready.’’