Dallas ? A federal judge on Friday ordered a now-defunct company in Richardson, Tex., to pay a $9 million fine within 3 1/2 years for what federal prosecutors had billed as the nation’s largest environmental-testing fraud case, in which more than 250,000 tests were in question.

U.S. District Judge Sidney Fitzwater also placed former lab employees Valerie Hong Truong, Rodney Roland and Victor Littles on probation for two years after they pleaded guilty earlier to reduced charges.

The sentencing capped years of investigations and a prosecution that took almost two years and involved a major setback for federal prosecutors.

Intertek Testing Services Environmental Laboratories and 13 former employees were accused of falsifying test data used to determine the safety of Superfund locations, landfills and other hazardous waste sites from New York to Hawaii. Suspect tests also were conducted at several Texas locations, including the closed RSR lead smelter in Dallas and the closed Kelly Air Force Base in San Antonio.

On Nov. 20, after a six-week trial with about 60 government witnesses, a federal jury in Dallas acquitted eight former managers and lab employees who had faced the most serious charges, including conspiracy to commit mail fraud, wire fraud and making false claims against the government.

Two other former lab employees, who pleaded guilty to reduced charges, were sentenced to probation terms Jan. 18.

The defunct Richardson lab’s parent company, Intertek Testing Services of London, has agreed to pay the $9 million fine as part of a plea agreement, Fitzwater said. The Richardson lab was closed in 1998.

Intertek’s New York attorney, John Kenney, declined to discuss the corporation’s decision to negotiate a plea bargain in which it admitted to failing to properly calibrate testing equipment and to submitting fraudulent test results.

Assistant U.S. Attorney John Bradford of Fort Worth, Tex.,the lead prosecutor, viewed the resolution of the case with mixed feelings.

“I’m satisfied with the outcome against the corporation, but I’m disappointed in the acquittals in the criminal case” on Nov. 20, he said. “It was the jury’s decision.”

Thousands of environmental safety tests that the company conducted between 1994 and 1997 were unreliable, and thousands of samples are no longer available for testing, according to federal prosecutors and Environmental Protection Agency officials.

Prosecutors and EPA officials questioned tests conducted on more than 250,000 air, liquid and soil samples from 59,000 projects at locations nationwide.