Caterpillar Inks Big Lease at Williams Square in Las Colinas The company has signed on for multiple floors in the project’s West Tower to house its new Electric Power division. Caterpillar Inc. has selected Las Colinas as the home base for its new Electric Power division. The company will lease multiple floors in the West Tower of Williams Square; it’s still determining exactly how many square feet it will ultimately take. Members of the group are currently located globally, with leadership in locations such as Houston and Atlanta. According to a company spokeswoman, employees will move to the new Irving office from several locations; Caterpillar also expects to make local hires, as well.