U.S. legal proceedings against Chinese drywall manufacturers could be speeded up by a concession made by a defendant, observers say.

Knauf Plasterboard Tianjin Co. Ltd., one of the major manufacturers being targeted in the case, has agreed not to demand that plaintiffs in a class-action lawsuit alleging defective materials use international rules in serving legal papers, The (New Orleans) Times-Picayune reported Tuesday.

An order issued Monday in New Orleans by U.S. District Court Judge Eldon Fallon indicated that Knauf has made a one-time offer that homeowners who sign up for the suit by Dec. 2 and show proof they have KPT drywall in their homes won't have to pay a $15,000 fee to serve the Chinese company through The Hague Convention, the newspaper said.

The suit's plaintiffs contend the Chinese-made drywall has sickened them by emitting toxic gases that corrode homebuilding materials.

"It's a substantial development in the case," plaintiffs' liaison counsel Leonard Davis told the newspaper.

"It's all about streamlining cases," added Kerry Miller, a New Orleans attorney who represents KPT. "What is the universe of claims? That's what we're trying to resolve. We would also hope our response pushes the others to become engaged and to be problem-solvers."