Mayor Bloomberg’s torn through $64.8 million in his quest for a third term, nearly 50 percent ahead of his 2005 pace, according to figures released yesterday.

At this point four years ago, the billionaire mayor had shelled out $46.6 million en route to spending $85 million, a US record for a local race.

“The only word that can be used for the amount of money that’s being spent is ‘obscene,'” said his Democratic rival, Comptroller Bill Thompson, who so far has raised $8 million.