updated 08/23/2011 AT 3:00 PM ET
•originally published 08/23/2011 AT 4:30 PM ET
It’s a boy and a girl for William Petersen.
The CSI actor, 58, and wife Gina Cirone welcomed twins via surrogate on July 5 in Los Angeles, PEOPLE confirms.
The pair were born prematurely, Petersen’s rep says, but are steadily improving.
“The babies are doing great and are improving every day and we can’t wait for them to come home,” the couple, who married in July 2003, tell PEOPLE.
Petersen is already dad to daughter Maite, 36, who has two young sons of her own.
After leaving CSI in 2009, Petersen was followed on the series by Laurence Fishburne, who has since been replaced by Ted Danson for the new season premiering in September.