As far as I remember, they were called LucasArts, except their first title (Labyrinth, 1986) was published and distributed by Activision. Everything else, from Maniac Mansion (1987) to Escape from Monkey Island (2000), was published by LucasArts.
/edit I stand corrected... I just checked the intro on the c64 version of Maniac Mansion, and it does indeed state Lucasfilm Games, not LucasArts. (https://www.youtube.com/watch?v=PM8ot8bJS3Q)
/edit I stand corrected... I just checked the intro on the c64 version of Maniac Mansion, and it does indeed state Lucasfilm Games, not LucasArts. (https://www.youtube.com/watch?v=PM8ot8bJS3Q)