BIRMINGHAM, Ala. (AP) _ DuPont is offering to pay $120 million to settle its share of claims filed over ruptured plastic plumbing installed in thousands of homes nationwide.

The lawsuits involve polybutylene plumbing, known as ``PB'' pipe and most easily recognized by its gray tint. DuPont's involvement stems from fittings made of the company's Delrin acetal plastic that was used in a relatively small number of the PB systems.

``Anyone with gray, plastic pipes in their house is very likely covered by this settlement,'' said plaintiff's lawyer Joe Whatley.

Whatley's firm represents a group of homeowners who filed a lawsuit in rural Greene County, about 90 miles southwest of Birmingham.

Lawyers for homeowners said they were still seeking billions of dollars more from two other companies, Shell Oil Co. and Hoechst Celanese Corp.

The DuPont money probably will not be paid until there is either a settlement or verdicts involving Shell and Hoechst Celanese, plaintiff's lawyer Pete Petroski said today.

``There's the possibility we still will be able to work out some kind of joint settlement,'' DuPont spokeswoman Diane Currie said from DuPont headquarters in Wilmington, Del.

Representatives of Shell and Hoechst Celanese did not immediately return phone calls for comment.

While the settlement is meant to resolve a total of 21 class-action cases nationwide, individual homeowners can still sue individually, she said.

Circuit Judge Eddie Hardaway granted preliminary approval of DuPont's offer Friday. No final decision is expected before fall, Whatley said.

DuPont's payment would mean as many as 930,000 homeowners could get $120 to $200 each, or 8 percent of the cost of installing new plumbing, based on figures provided by the company.

Details including how homeowners can apply to join the settlement will be announced later this year as part of a nationwide notification campaign.

DuPont, Shell and Hoechst Celanese reached a $750 million settlement last October, but a judge in Texas threw out the accord in February without stating her reason.

PB pipes were commonly installed in mobile homes, apartments and budget-priced houses for almost 20 years. The pipes and their fittings often sprung leaks as they aged.

Plaintiff lawyers argued the leaks were caused by exposure to the chlorine contained in normal tap water. The companies blamed the problem on factors including improper installation and denied any liability.

DuPont took Delrin off the market for pipe-fitting applications when it became apparent the pipes were springing leaks.