The U.S. Department of Justice has accused several Houston-area landlords of colluding to inflate rent prices, expanding its antitrust case against RealPage, a Texas-based company whose software at the center of an alleged rent price-fixing effort.

The U.S. Justice Department is suing several landlords for allegedly coordinating to keep Americans' rents high by using both an algorithm to help set rents and privately sharing sensitive information with their own competitors to boost profits.

The U.S. Department of Justice and 10 state attorneys general have ramped up their antitrust lawsuit against RealPage, a property management software compa