A source has confirmed to that the organizers of Macy’s annual Thanksgiving Day parade were instructed by NBC, which broadcasts the event, to rescind an offer for the cast of rival network Fox’s hit series Glee to perform in the parade. (TMZ first reported the story.) Fox and NBC had no comment.

UPDATE: Macy’s spokesperson Orlando Veras sent this statement: “As with any live event, the talent booking process is a fluid one subject to frequent updates or changes. Due to this fact, we don’t confirm talent appearances for the Macy’s Thanksgiving Day Parade until early November when the final line-up is determined.”

UPDATE 2: Another source close to the event confirmed to that while the parade has featured talent from other networks — American Idol singers, High School Musical actors — there was concern that featuring the entire cast of a rival’s show amounted to outright promotion.