The Crazy Frog's Axel F is currently outselling the British band Coldplay's new single, Speed of Sound, according to early retail reports.
HMV said the Crazy Frog was now almost certain to top the new chart.
"The Crazy Frog is now almost certain to be number one, when the next Official UK Chart is announced on Sunday, selling well over 100,000 copies in the process," said HMV spokesman Gennaro Castaldo.
"It also means this will be the first time that a song that has been popularised as a ringtone has also crossed over into the singles charts in this way," he said.
"Music purists might not be too happy at the prospect of the Crazy Frog outselling Coldplay. But it shouldn't come as that much of a surprise when you consider its huge novelty appeal and the massive amount of exposure it's currently getting," added Castaldo.
"Kids obviously find it cute and cool, but students and even office workers seem to be drawn to its rather kitsch, ironic appeal. The only real issue is whether the record label can press enough copies to keep up with the huge demand that we're seeing right now," he said.
A new version of the Beverly Hills Cop movie theme tune by Harold Faltermeyer, which reached number two in the UK 20 years ago, the profile of the Crazy Frog mobile phone ringtone has been raised in recent months through heavy television advertising, said the BBC.
