The city’s tab for a class-action lawsuit over a racially biased teaching exam has hit $330 million — and could eventually exceed $1 billion, court papers show.

The long-running case relates to the state-mandated certification exam, known as the Liberal Arts and Sciences Test, which city teachers and DOE applicants took from 1993 to 2004.

A federal judge ruled in 2012 that the test was racially discriminatory and wrongfully prevented legions of black and Latino plaintiffs from either being promoted or hired by the DOE.

A special master was appointed to determine payouts for roughly 4,000 plaintiffs — and has awarded $333,212,230 for 1,190 claimants thus far.

The largest single award, court papers state, has been $1.8 million.

The Law Department — which is appealing the payouts — noted that the special master and assorted consultants have billed the city for an additional $25 million.

“We’re appealing the judgments because the methodology used by the Special Master is not solidly grounded in law and results in a windfall to some claimants,” said a city Law Department spokesman. “The City believes in fairness for all its employees, but it has been burdened with liability in this case based on a test developed and mandated by the state.”

Four teachers first filed a suit over the test in 1996 against the state and city, but an appeals court later detached Albany from the costly case.