Motorola, Blackberry Maker Sue Each Other

Motorola Inc. and Research In Motion Ltd. have sued each other over mobile-phone patents, each claiming the other is using handset technology without permission. Motorola, the biggest U.S. maker of mobile phones, on Saturday asked a U.S. judge in Marshall, Texas, to order Research In Motion to stop the infringement. That company filed its own suit in federal court in Dallas the same day over similar claims. Winning the dispute would help the victor bolster its rank in the market for "smart phones" that can send e-mail, whose sales are growing almost six times as fast as that of the overall industry.