Gene T. Meyer, already serving a sentence of life plus 30 years for murdering a friend's wife, was convicted yesterday of trying to hire another man to kill four persons, including his own wife and two police detectives.

Prince George's County Circuit Judge Howard S. Chasanow, who added 80 years to Meyer's prison term following the jury conviction, said the case had the "most unfathomable set of circumstances I can imagine."

According to testimony at the three day trial, the man Meyer approached in an effort to have his wife, Hortensia, acquaintance Lon Lewis and Prince George's police detectives David R. Hatfield and Michael Morrissette killed was an undercover state police officier.

Prosecutors said Meyer solicited the slayings while waiting to be sentenced in May 1978 on his previous death for Lewi's wife and infant daughter in a "you kill my wife, I'll kill yours" scheme.Lewis has also been sentenced to life in prison for that scheme.

The jury in Meyer's latest trial heard several hours of tape recorded conversations made by the undercover state policeman without Meyer's knowledge in his jail cell in Upper Marlboro. The subject of discussion was how much Meyer would pay to arrange for the murder's he wanted.

In closing arguments yesterday, Deputy State's Attorney Joseph Sauerwein asked jurors to place themselves in the position of the potential murder victims. "This defendant would have done anything to accomplish the purposes of having you dead," he declared.

Meyer's attorneys argued that he had been put on the murder plot by an informant and argued that because Meyer is now incarcerated at the state's Patuxent Institution, a correctional facility that stresses rehabilitation, he should be granted leniency.

The jury found Meyer guilty of four counts of solicitation to murder. Judge Chasanow sentence Meyer to four consecutive prison terms. Meyer could be eligible for parole in 20 years.