MySpace promoted Hirschhorn and Jones to revitalise the social networking portal after chief executive Owen Van Natta left in February this year.
Hirschhorn was previously the chief product officer before stepping up at MySpace. He also worked as the president of Sling Media's Entertainment Group before joining News Corp.
Hirschhorn confirmed his departure through Twitter earlier today and is returning to New York.
MySpace, once the largest global internet social network, recorded only 111 million unique users in April, compare to 519 million on Facebook, according to comScore.
MySpace is not expecting to lose momentum against rivals Facebook and Twitter. eMarketer projects that MySpace will earn US$385 million from ad sales in 2010.