MOSCOW – One of the key leaders of Georgia’s Rose Revolution, Prime Minister Zhvania, died yesterday in a bizarre gas poisoning, robbing the volatile ex-Soviet republic of its steadiest political hand.

Zhvania was found dead in a friend’s apartment from an apparent gas leak. While authorities insisted his death was accidental, some Georgians remained suspicious considering the country’s history of political violence.

Experts warned that Zhvania’s death could destabilize poverty-stricken Georgia, which is battling endemic corruption and conflicts in Kremlin backed separatist regions.

He was named premier after fellow revolutionary leader Mikheil Saakashvili, the former New York lawyer, was elected president in January 2004, and was widely seen as a positive influence on the fiery and provocative Mr. Saakashvili.

“He was one of the only experienced politicians in the government and if Saakashvili listened to anyone, it was him,” a prominent political analyst, Archil Gegeshidze, said. “Zhvania gave some balance to the government and was able to have a moderating influence on Saakashvili.”

Mr. Gegeshidze said Zhvania had been handling Georgia’s toughest problems: reforming the economy by tackling widespread corruption and negotiating with separatist leaders.

“He was one of the most respected, if not the most respected, politician in the country. Without him the Georgian government is beheaded and has become more vulnerable.”

Hundreds of Georgians gathered outside the home of Zhvania’s mother in central Tbilisi last night to watch the delivery of a brown wooden coffin. His funeral is scheduled for Sunday.

“In Zurab Zhvania, Georgia has lost a great patriot, who devoted his entire life to serving the motherland. Zurab’s death is a great blow to Georgia and to me personally. I lost a very close friend, a reliable adviser, and a great ally,” Mr. Saakashvili said. “I want to call on you all to be strong, because there is no greater responsibility than loyal service to our country and our people.”

Mr. Saakashvili also urged Georgians to remain calm, saying, “I assume control over the executive branch and I call on members of the Cabinet to return to work and to continue their work as normal.”

Georgian radio reported that the deputy premier, David Baramidze, has been named acting prime minister.

The longtime Georgian leader who was forced from power by the Rose Revolution, Eduard Shevardnadze, called the death “an irreparable loss.”

Zhvania was found dead in a friend’s apartment following an apparent gas leak from a heater. The 41-year-old prime minister was found along with his friend Zurab Usupov, the deputy governor of a local region, in Usupov’s Tbilisi apartment at about 4 a.m. Georgian time yesterday. Security guards who had accompanied Zhvania to the apartment broke through a window after hearing nothing from inside the apartment for several hours.

In the main room stood a gas-fired heating stove, a common feature in Georgia, where central heating is virtually nonexistent. Zhvania’s body was slumped in a chair, and Usupov’s was found in the kitchen. An open backgammon set was lying on a table in the room, along with a loaf of bread and pieces of sausage.

Authorities said an autopsy is under way and initial tests showed Zhvania’s blood had nearly double the fatal level of carbon monoxide. FBI experts are expected to help conduct forensics tests.

“It is an accident,” the interior minister, Vano Merabishvili, said. “We can say that poisoning by gas took place.”

While authorities said there was no reason to suspect foul play, many Georgians were skeptical.

One Georgian lawmaker, Alexander Shalamberidze, linked Zhvania’s death to a car bombing that killed three policemen earlier this week. In remarks clearly aimed at former imperial master Russia, he said, “outside forces” were involved in both the explosion and Mr. Zhvania’s death.

The Russian foreign minister, Sergei Lavrov, rejected any connection with the death.

“The statements of those who rush to make judgments … will remain on their conscience,” Mr. Lavrov told reporters. He said allegations of foul play aimed at Russia “do not help find the truth and do not promote the development of Russian-Georgian relations.”

President Putin sent a telegram of condolence, praising Zhvania for his efforts to improve relations between Russia and Georgia.

Russia backs two separatist regions in Georgia – Abkhazia and South Ossetia – that broke away from the central government after wars in the 1990s. Tensions occasionally flare, and gunfights and shelling are not uncommon, especially in and around South Ossetia.

Zhvania was a rare figure respected on both sides of the disputes.

A minister in South Ossetia’s separatist government, Boris Chochiyev, praised Zhvania as “among the Georgian politicians who favored a peaceful settlement of the conflict. I can say that he represented the party of peace.”

A Russian parliamentarian, Konstantin Zatulin, was quoted by Interfax yesterday as warning that Zhvania’s death was bound to increase tensions.

“It does not promise anything good from the point of view of bringing the situation back to normal,” he said. “I do not rule out that Saakashvili may launch some shady scheme which Zhvania most likely would have opposed.”