"The Orthodox have a different practice,” he told reporters July 28 during his flight back to Rome from Rio de Janeiro. The Orthodox “follow the theology of ‘oikonomia’ (economy or stewardship), as they call it, and give a second possibility; they permit” a second marriage. While the Greek Orthodox Archdiocese of America and the Greek Orthodox Archdiocese of Thyateira and Great Britain both use the English term “ecclesiastical divorce” when referring to the use of “oikonomia” to permit a second marriage, Orthodox scholars and the websites of both archdiocese make clear that the Orthodox practice differs from both a Catholic annulment and a civil divorce. Unlike an annulment, which declares that a union was invalid from the beginning, the Orthodox decree does not question the initial validity of a sacramental marriage and unlike a civil divorce it does not dissolve a marriage. Rather, the Orthodox describe it as a recognition that a marriage has ended because of the failure or sin of one or both spouses. As quoted on the British church’s website, Metropolitan Kallistos of Diokleia, an Orthodox scholar and retired professor at Britain’s Oxford University, wrote in his book, “The Orthodox Church,” that the Orthodox permit divorce and remarriage under certain circumstances because Jesus himself, in upholding the indissolubility of marriage in Matthew 19:9, makes room for an exception. In the translation he quoted, Jesus says: “If a man divorces his wife, for any cause other than unchastity, and marries another, he commits adultery.”
http://www.catholicfreepress.org/vatican/2013/08/06/speaking-of-divorce-pope-refers-to-practice-of-orthodox-churches/