A 28-year-old convicted rapist was found guilty last night of murdering and attempting to rape a Japanese woman enrolled at the University of Maryland four years ago.

A Prince George's Circuit Court jury, which deliberated more than 25 hours over two days, also found the man, Howard E. Hines of Alabama, guilty of a third degree sex offense in connection with the death of Michioyo Nakada, 23.

The same jury will reconvene July 6 for a death-penalty hearing to determine whether Hines should be put to death in Maryland's gas chamber.

Nakada, who had come to the United States from the University of Okinawa to study psychology in 1975, was found in a wooded area near her apartment in Hyattsville. She had been stabbed 40 times in the neck and chest, and parts of her nude body had been burned.

An early suspect in the case, Hines was not arrested until 1982, when he was located in an Alabama prison serving a sentence for rape.

Hines, who sat calmly, occasionally chewing his finger tips as the lengthy verdict was read, admitted he was near the wooded area where the murder occurred June 21, 1979, but denied he killed the woman.

He had applied for a job at the apartment complex the day before the killing, and spent the night there. Several residents of the area testified during the trial that they had seen him in the area at the time of the murder, that he had seemed nervous and that he had disappeared shortly after the body was found. One witness said she had seen him crouched over the body.

Prosecutor David M. Simpson admitted to jurors that his case against Hines was "circumstantial," but argued there was no doubt Hines was the culprit. Joseph M. Niland, one of Hines' two attorneys, had called the case "woefully inadequate" in proving Hines' guilt.

Defense attorney Eugene M. Yannon told Circuit Judge Audrey E. Melbourne after the verdict was announced at 7:15 p.m. yesterday that psychological evalations of Hines, which were not used during the trial, would be used during the death-penalty hearing.

Niland told jurors during closing arguments Thursday that Nakada was the victim of "no more than a second degree murder," arguing that the nature of her death indicated the killer was frenzied and not acting deliberately. Prosecutor Simpson said, referring to the stab wounds, that there were "over 40 points of deliberation."