ATHENS (Reuters) - Fofi Gennimata, the leader of Greece's socialist opposition Movement for Change, died on Monday after a long battle with cancer.

       The death of Gennimata, who was 57, was announced by the Evangelismos hospital where she had been receiving treatment in recent weeks.

       Greek Prime Minister Kyriakos Mitsotakis was 'shocked' to learn of Gennimata's death, his office said in a statement.

       Mitsotakis, who arrived in Saudi Arabia on a two-day visit on Monday, would be changing his schedule and returning to Greece on Tuesday evening, his office said. A tour of Greek islands scheduled for Wednesday and Thursday was also cancelled.

       Gennimata was elected leader of the former ruling PASOK party in 2015, and in 2017 was appointed president of the Movement for Change, a coalition of centre-left parties that was formed around PASOK.

       Gennimata was the daughter of Greek politician Georgios Gennimatas who was a founder member of PASOK, which was dominant in Greece in the eighties and nineties. A mother of three, she was first elected to parliament in 2000.

       (Reporting by Angeliki Koutantou, Editing by Timothy Heritage)