Complex sentence: Even his car alarm caused controversy as United Artists Corporation filed and application to oppose the registration of Rolo's trademark "Black Panther" without declaring the grounds for their opposition, only that they were the owners of the Pink Panther character.
Split into simpler sentences: Even his car alarm caused controversy as United Artists Corporation filed an application to oppose the registration of Rolo's trademark "Black Panther". UAC did not state the grounds for their opposition, only that they were the owners of the Pink Panther character.