BOSTON (Reuters) - Two U.S. companies found liable for creating a public nuisance by manufacturing lead paint took their case to Rhode Island's highest court on Friday after a judge rejected their bid for a new trial.

Sherwin-Williams Co. and NL Industries Inc. were among three companies accused by Rhode Island of covering up the health risks of lead paint in a lawsuit filed in 1999, the first in the nation to hold paint makers responsible.

The appeal came after a Superior Court judge entered a final judgment in the case on Friday that was in-line with a jury verdict last year that found the two companies and another former paint maker, Millennium Holdings LLC, liable.

Rhode Island's case could influence court decisions in other states, counties and cities where lead-poisoning lawsuits are pending, and it has drawn comparisons with multibillion-dollar judgments against tobacco makers.

The three companies have been ordered to clean up buildings contaminated with lead paint in the state, which could cost as much as $3 billion.

"This is a historic day in our continuing fight to protect Rhode Island's children from the harmful consequences of lead poisoning," state attorney general Patrick Lynch said. "Now is the time to get to work on cleaning up the mess."

The U.S. government banned lead paint in 1978 after studies showed it caused health problems in children, including learning disabilities and permanent brain damage.

But it remains widespread, especially in older homes in the northeastern United States. Rhode Island children routinely test above the national average for blood-lead levels.

Rhode Island authorities say more than 30,000 children were poisoned by lead paint in the state, with an estimated 200,000 to 300,000 homes contaminated by the paint. The cost of cleaning one home is estimated at up to $15,000, said Lynch.

The paint companies have denied they were directly responsible, saying landlords not paint makers should be held accountable for conditions that expose children to lead.

Rhode Island Superior Court Judge Michael Silverstein rejected a bid for a new trial last month.