Rioting prisoners at the West Virginia Penitentiary today released six more hostages seized during Wednesday's takeover of the maximum-security prison, after receiving assurances of a meeting Friday with Gov. Arch A. Moore Jr.

Under the terms of an unusual agreement signed today, the inmates are to release their seven remaining hostages Friday morning and return to their cells; Moore then is to meet with a handful of their representatives.

State officials also agreed that there would be no reprisals against the inmates for the uprising, in which at least two prisoners have been killed and 16 hostages seized. Three hostages were released earlier.

John Price, a spokesman for the governor, said the no-reprisal agreement would not cover any prisoner deaths.

Late tonight, prison officials said they had been notified that Richard Harold Dean, who had been serving 15 years on a kidnaping conviction, was dead. Earlier, the body of another inmate, identified as Kent Slie, 38, who was serving a life term for murder, also was found inside the prison. Officials have said they will await autopsy results on Slie and Dean before commenting further on their deaths.

The six hostages released today were taken by ambulance to a nearby hospital. A spokesman there said they had suffered "minor cuts, bruises and mental stress," but otherwise appeared uninjured.

One of those released today, Maj. Edward Littell, 33, said, "I did a lot of praying. I had a lot of people doing a lot of praying for me." Littell said he suffered bruises and muscle damage during the takeover.

The New Year's Day uprising, which began in the prison's cafeteria at dinner time, apparently was sparked by prisoner complaints over crowded and unsanitary conditions that have been the subject of numerous official reports and a 1983 court ruling.

At a meeting with reporters today, two inmates -- both convicted murderers serving life sentences -- told of cells that are too hot in the summer and cold in the winter.

"We want to be treated with dignity, like the people that we are," said one of the men, Alvin Gregory. "We don't see why we have to sleep in 10-degree weather in the winter, and we don't see why we have to sleep in 110-degree weather in the summer."

After the meeting, Price, the governor's press secretary, gave further details of the prisoners' demands. "Better food," he said. "They want to be able to grow their hair long. They want at least one hot meal a day . . . . They expect to be treated with more respect and more dignity as human beings."

A West Virginia Community College professor who for the last 15 months has monitored the prison, located in the state's panhandle just south of Wheeling, agreed that conditions at the 120-year-old facility were at least as bad as the prisoners described.

Prof. Donald Poffenberger was appointed special master by a county court in 1984 to oversee improvements in the prison, but he said officials have taken no action to remedy the problems the court found.

"You're dealing with a 100-year-old institution," he said. "The last time any renovation was done there was the late 1920s."

Based on his inspections, videotapes and interviews with prisoners, Poffenberger said, the prison environment "was consistently found to be malodorous. There is a problem with the plumbing that causes raw sewage to collect in the basement areas . . . . General sanitation has been a problem."

Poffenberger said he recorded temperatures inside the prison of 30 degrees during the daytime last January and in the "high 90s" last summer -- well outside the comfort zone of 66 to 80 degrees recommended by the American Correctional Association.

Also, Poffenberger said, meals served to prisoners confined to their cells are usually cold, and the prison diet lacks sufficient minerals and vitamins. During one random 30-day check, Poffenberger said, beans were served 15 days, "without an exaggeration. There was very little variety in the food."

Officials of this poor, coal-mining state are caught between the 1983 court order to improve the facility and the $19 million the needed repairs are estimated to cost.

The situation is expected to get worse, as mandatory minimum sentences recently passed by the legislature go into effect. The prison, which resembles a Tudor-style castle in the English countryside, was built to accommodate 650 prisoners but held as many as 750 as recently as Christmas Day.

The uprising here apparently was spontaneous, according to officials and the two inmates who talked to reporters.

"There didn't seem to be a whole lot of planning involved," said Price, the governor's spokesman.

While officials have said Slie was killed by fellow inmates, the two prisoners who spoke to reporters today said only that he was found lying in the hallway outside his cell after the violence began.

Word of Dean's death came as a surprise to prison officials, since the siege seemed all but ended tonight following this afternoon's agreement. "We have no information why or how" he was killed, said Jerrie Clutter, secretary to the warden. "It could have happened anytime, from the time of the takeover until we received the body at 8 p.m."

The two prisoners who spoke with reporters met with them and state officials in a visitors' lounge far from the cell blocks. They spoke extemporaneously and emotionally, repeatedly questioning whether state officials intended to live up to the agreement with the inmates.

The officials, including the state's corrections commissioner, signed the document but the prisoners did not.

Keeping to the terms of the pact, however, the inmates released six hostages at about 4 p.m.

Moore, who out of the state today and Wednesday, when the uprising began, agreed to meet with the riot leaders but "only after control of the institution was returned to the state," Price said.

He added that "control" meant that all prisoners were back in their cells and all hostages released.

The governor's office denied a report that Moore was in Florida attending a New Year's Day college football bowl game as the hostage situation unfolded.

It was unclear why the inmates decided to keep seven hostages until Friday morning.

"They indicated that they wanted time to clean the place up. It may sound hard to believe," Price said.

He added that there appeared to be damage inside the prison, but he would not estimate the extent of it.

Prisoners rioted here in 1973. Six years later 15 inmates broke out, leaving one prisoner and one state police officer dead.