The move leaves Paul Murray and his Blue Knights consortium and US bidder Bill Miller in a head-to-head shoot-out for the stricken Scottish Premier League club.
Mr Ng had become increasingly frustrated at the takeover process in recent days as the clubs administrators, Duff and Phelps, continue to delay making an announcement as to who would be handed preferred bidder status.
His patience now seems to have worn out, with the 52-year-old dramatically taking his bid off the table this morning, an announcement he has made "with deep regret".
It is believed Ng has concerns over Duff and Phelps' ability to deliver the 85% shareholding currently owned by chairman Craig Whyte, who bought the club from Sir David Murray last May in a £1 deal, claiming the process is now "untenable".
And the Evening Times understands that the Blue Knights also believe Duff and Phelps failure to secure Whyte's shares could yet prove to be a deal-breaker unless they address the issue very quickly.
The shock news leaves Rangers fans in limbo once more, with just two bids now seemingly on the table to rescue the club and save them from going into liquidation after Sale Sharks owner Brian Kennedy was told his latest offer was not acceptable yesterday afternoon.
Ex-Ibrox director Murray stepped back from the process at the start of this week but supporters will now pin their hopes on the Blue Knight landing control of the club, with fears over Miller's motives as he steps up his takeover move.
Miller has already held talks with Gers boss Ally McCoist but fans are sceptical over his plans for the future, with the trucking tycoon is expected to confirm his vision for the future later today.
The American, who was involved with the controversial bid from Chicago-based Club 9 Sports before launching his own deal, will have to convince supporters that he has no plans to liquidate the 140-year-old club, as well as hold talks with Whyte in a bid to strike a deal to land his majority shareholding.