Owners of thousands of U.S. homes tainted with foul-smelling Chinese drywall agreed to a legal settlement on Thursday with a German manufacturer. An attorney for the plaintiffs, Russ Herman, said the settlement reached with Knauf International was worth $800 million to $1 billion, but a lawyer for the company said the final amount would likely be much lower. Knauf International’s Chinese subsidiary made the tainted product, which has been blamed for producing a stench and fumes that damage air conditioning, wiring and fixtures.