Construction-equipment maker Caterpillar ( CAT) said it will produce a line of electric drive mining trucks. As a part of the move, the company announced an alliance with Mitsubishi Electric. The partnership will give Caterpillar dealers and customers access to a broader portfolio of mining truck drivetrain technologies, it said. Mitsubishi Electric will supply power semiconductors, one of the key systems for Caterpillar's mining trucks. Details regarding the size and range of the company's electric drive offering are still under consideration, it said. However, it expects pilot testing on the new line to begin in the next 18 months. The company's stock closed Thursday at $72.43, down $1.27, or 1.7%.