02/02/2008 at 04:00 PM EST
Friends and celebrity colleagues – including Tom Cruise
and Katie Holmes
, Sienna Miller
, Ellen DeGeneres
and director Todd Haynes – gathered on the Sony lot in Los Angeles to remember Heath Ledger
on Saturday, PEOPLE has confirmed.
The gathering also included Ledger's father Kim, industry luminaries and those connected to CAA (the agency that represented Ledger), including Cruise and Holmes, who costarred with Michelle Williams on Dawson's Creek
. It comes a week after relatives and close friends – including ex-girlfriend Naomi Watts
– paid tribute
to the 28-year-old actor at a smaller service at an L.A. cemetery.
Saturday's service began around noon on the lot, which is closed to the public. Attendees included Miller, Ledger's Casanova
costar, and Shannyn Sossamon, who starred with Ledger in A Knight's Tale
. Speakers included Haynes, who directed him in last year's Bob Dylan film I'm Not There
With reporting by JENNIFER GARCIA, ELIZABETH LEONARD and CYNTHIA WANG