Research in Motion this week sued rival cellphone manufacturer LG for trademark infringement in a Los Angeles court, claiming that several of the latter’s phones are unfairly profiting from their similarity to the BlackBerry name. LG’s style-oriented Black Label series of phones such as the Shine and specific Chocolate phone color schemes such as Black Cherry and Strawberry might cause confusion for buyers unaware of the difference, RIM says. The complaint would collect damages and also block LG from using the relevant names for its products. Though it is believed to be responsible for naming the Chocolate models, Verizon is not named in the lawsuit.

The BlackBerry maker has been aggressive in protecting its name, having settled a like-minded suit in February that complained Samsung’s BlackJack smartphones were capitalizing on RIM’s success. Neither the Canadian company nor its Korean target LG have been available for comment on the lawsuit or its choice of venue, which is considered a middle-ground between the two companies.