The New York Times’ ombudsman says the newspaper violated its standards when it gave the liberal group MoveOn.org a $77,508 price break on a full-page advertisement that labelled Gen. David H. Petraeus as Gen. Betray Us.

The organization paid $64,575, instead of the standard $142,083 for the ad questioning the war in Iraq, the newspaper’s public editor, Clark Hoyt, wrote in a column published yesterday.

Times spokeswoman Catherine Mathis told Hoyt that an advertising sales representative shouldn’t have agreed to the discounted price. The Times’ internal advertising standards bans ads involving attacks of a personal nature, Hoyt wrote. Plus, discounted ads are supposed to be given a “floating date” for publication, but MoveOn.org was guaranteed a Sept. 10 placement.

“We made a mistake,” Mathis told Hoyt.