Complex sentence: It was once the largest manufacturer of holiday lighting in the world, but since 1967 has existed only as a licensed trademark, which is now held by Inliten, LLC, of Glenview, Illinois.
Split into simpler sentences: It was once the largest manufacturer of holiday lighting in the world, but since 1967 has existed only as a licensed trademark. It is now held by Inliten, LLC, of Glenview, Illinois.