Rohm & Haas is selling a California chemical plant.

In order to satisfy antitrust concerns contained in a lawsuit filed by the Justice Department, the Philadelphia company said it will sell the Redwood City plant that it acquired two years ago from Duolite International, a subsidiary of Diamond Shamrock. The government sued the company, saying its purchase of the chemical plant may substantially reduce competition for a specialty product used in water treatment. According to documents filed in court, the company has agreed to divest the plant.