Shares of Research In Motion (maker of the popular BlackBerry) fell in trading Monday due to increased speculation that Motorola will release a BlackBerry competitor. Dubbed the RAZRBerry, the device is supposed to mimmick the design of RIM’s flagship product. Purported design mockups leaked online late last month.

Barron’s cover story [subscription req.] this week is on Motorola and talks about the RAZRBerry. After the article hit newswires shares of Research In Motion [RIMM] fell nearly 5%.

Motorola has a launch event dubbed MOTONOW scheduled for this evening.