Aston was originally seeking a float at $A8.20 per share but this was scaled down to $5.96 a share in recent weeks as institutional interest failed to meet expectations.
By yesterday afternoon the shares lost 26c to close at $5.71.
The first day of trading cut the $400 million float’s value by more than $16 million.
Tinkler remains the major stakeholder and owns 35% through his private company Aston Resources Investments.
Commodities trader Noble Group was touted to become a significant shareholder a few weeks ago, but its subsidiary Osendo ended up with a 4.8% stake in Aston.
Japanese trading house Itochu Corporation was also rumoured to be keen on the float but only took up a 2.7% interest.
Aston bought its flagship Maules Creek project off Rio Tinto subsidiary Coal & Allied for $480 million in November 2009.
Mine Life senior resources analyst Gavin Wendt was not bullish on the Aston float when he spoke to ILN more than a week ago.
“Rio has always been interested in first-rate projects,” Wendt said.
“These projects that require big investment but aren’t first rate might sort of struggle for a little bit longer.”
Located in the Gunnedah Basin of New South Wales, the project is targeting 13 million tonnes per annum of raw coal for at least 21 years of open cut mining, with development scheduled to start in the December quarter of 2011.
The coal reserves total about 240Mt while total resources are estimated to be 610Mt of thermal and semi-soft coking coal.
Aston shares are down a further 13c or 2.3% this morning to $5.55.