The statement, issued by a spokesman for Schwarzenegger, said the two were working on the future of their relationship while living apart and would continue to parent their four children together.
The couple said in a statement to the L.A. Times, "This has been a time of great personal and professional transition for each of us. After a great deal of thought, reflection, discussion and prayer, we came to this decision together.
At this time, we are living apart while we work on the future of our relationship".
The L.A. Times reports that the couple met in 1977, when NBC's Tom Brokaw introduced Shriver to Schwarzenegger at a charity tennis tournament. The separation announcement comes months after the death of Shriver's father, Peace Corps founder and former vice presidential candidate Sargent Shriver, in January.