Jennie Garth and Peter Facinelli
03/28/2012 AT 08:30 PM EDT
03/28/2012 AT 06:30 PM EDT
Peter Facinelli has made it official and filed for divorce from Jennie Garth after 11 years of marriage.
In the Los Angeles Superior Court petition filed Wednesday the actor cites the usual "irreconcilable differences" and seeks joint custody of their three daughters.
According to Facinelli, they separated on Jan. 1 – more than three months before the split was announced – after nearly 11 years of marriage.
After the annoucement
on March 13, Facinelli, 38, and Garth, 39, stepped out separately in public without their wedding rings.
The former couple and parents to Luca, 14, Lola, 9, and Fiona, 5, briefly reunited
last weekend for a shopping trip to a toy store with Lola and Fiona.
"You get the rug pulled from under you," the Beverly Hills, 90210
actress tells PEOPLE of Facinelli's decision
to end their marriage. "I have no landscape of what my future will look like, where before I had something that I can count on."
Since the split, Garth and Facinelli have shared parenting duties and plan on sharing joint custody of the girls, who have been living with their mother on the family's Santa Ynez, Calif. ranch.
Both newly-single actors have busy work schedules ahead: Garth, who turns 40 on April 3, has a new CMT reality show
, Jennie Garth: A Little Bit Country
, premiering April 20, that chronicles her move from L.A. to the country with the kids.
Facinelli, who plays Carlisle Cullen in the film adaptations of the Twilight
series, is a regular on Showtime's dark comedy Nurse Jackie
, which kicks off its fourth season on April 8.
Facinelli and Garth met on the set of TV movie, An Unfinished Affair
in 1996, and married in 2001.