Gillian Anderson and Mark Griffiths
08/07/2012 at 08:00 PM EDT
Gillian Anderson is single again.
The former X-Files
star, 43, has parted ways with Mark Griffiths, her partner since 2006, her rep confirms to PEOPLE.
They have two children
, sons Oscar, 5, and Felix, 3.
This is not the first serious relationship that has ended for Anderson. She split from husband Clyde Klotz – with whom she has a daughter – in 1997, and with second husband
Julian Ozanne in 2006.