230letterjuliet051210_18_X17-1.jpgThey just announced their split last month, but Peter Facinelli has taken the next step to make it official by filing for divorce from Jennie Garth, after 11 years of marriage in an LA Superior Court, on Wednesday.

The Twilight star cited "irreconcilable differences" and requests joint custody of their three daughters, noting they separated on Jan. 1.

The couple announced their split on March 13, and will now have to negotiate custody terms over daughters Luca, 14, Lola, 9, and Fiona, 5.

The former Beverly Hills 90210 star has been keeping busy working on her new CMT reality show, Jennie Garth: A Little Bit Country, which chronicles her move from LA to to a quiet farm in Santa Ynez, Calif.

The upcoming reality series will touch on the former couple's split and premiers on April 20, while Facinelli will be busy working on Showtime's Nurse Jackie, which kicks off its fourth season on April 8.