John Lennon's family is marking the 40th anniversary of "Give Peace a Chance," by donating the net proceeds from the sale of a commemorative digital single to the United Nations Peacebuilding Fund (PBF), according to a press release.

In a rare, unified move, Yoko Ono, Sean Lennon and Julian Lennon launched the single yesterday (11/3) exclusively at Apple's iTunes store. Net proceeds from all sales through Dec. 31 will benefit PBF.

"I am thrilled that so many in the music business are readily supporting 'Give Peace a Chance' on its 40th anniversary," Ono said in a statement. "It is indeed a time when we are all getting more aware of the necessity of doing something to achieve world peace, no matter how small. ... I feel deeply that we are all one, regardless of where we stand."

Ono and Lennon wrote the peace anthem during their March 1969 honeymoon bed-in protest against the Vietnam War. The song originally was released by the Plastic Ono Band on July 4, 1969.