Official Chinese news reports today cast Vice Chairman Deng Xiaoping in an active leadership role, apparently seeking to dampen speculation about the mysterious, month-long disappearance of China's most powerful politician.

Meanwhile, reliable Peking sources said Deng is presiding over a high-level Communist Party meeting here attended by top provincial officials who are preparing for the coming campaign to cleanse China's bloated and corrupt bureaucracy.

Deng, 77, was last seen in public Jan. 12, prompting suggestions from foreign observers that he was gravely ill or had been toppled from power by the military. Other analysts believe he is working behind the scenes to orchestrate the controversial bureaucratic housecleaning.

Deng's unexplained absence has inspired intense interest here because of his vital role in China's fractious political realm. He is considered the only leader with the acumen and contacts to balance conflicting political forces.

Two leading newspapers, including the party organ People's Daily, published prominent front-page stories indicating that reports of Deng's political demise were premature. Few references to Deng have been made in the media since he disappeared.

The People's Daily reported that Deng, who is chairman of the powerful military affairs commission, recently instructed the Army to guide the national reforestation drive. It said Deng's orders were passed along to the Army logistics department.

The second reference came in the main story of China Daily, an English language newspaper that is widely circulated among foreign journalists, diplomats and businessmen based in Peking.

Vice Premier Bo Yibo is quoted in the article as lavishing praise on Deng's command and repeating Deng's characterization of the forthcoming bureaucratic trimming as "another revolution."

Bo said that foreign talk of a purge "is entirely groundless." It is unclear if he was referring to a purge of Deng or other officials who would lose their jobs in the government and party remodeling.

Noting the importance of the housecleaning and Deng's role in inspiring it, Bo said, "Of course, a considerable number of old cadres will be retired from active duty, some will move back to what we call the second line to serve as advisers."

He apparently sought to clarify remarks made last Saturday by Vice Premier Wan Li, who said Deng has "withdrawn to the second line" of leadership, turning over daily decision-making to younger men while continuing to focus on major policy issues.

The official New China News Agency announced the purge of 276 officials from a single ministry Saturday in a dramatic indication of the massive scale of the bureaucratic reorganization, United Press International reported.

In the Third Machine Building Ministry, seven of nine vice ministers were asked to retire and serve as advisers and another 269 lower ranking officers who were too old to perform their duties were moved out of active duty.

In a dramatic indication of how deeply the bureaucracy is to be trimmed, officials replaced those fired with 30 persons "in their prime of life," the Chinese news service said. Diplomats believe the seven machine-building ministries are to be combined into one.

Although he said Deng was in good health and had been resting in southern China, Wan deepened the mystery of Deng's absence by failing to explain why he had not appeared in a newspaper photograph or come out for a brief public showing to quell rumors.

Amid growing speculation, China's Foreign Ministry on Thursday issued a statement affirming that Deng still is vice chairman of the party's ruling Central Committee and head of the commission that runs the 4-million-member military.

The ministry pointed out that Peking began to elevate younger officials to leading posts in February 1980, when Deng and other aged vice premiers stepped down from their government jobs while retaining their party positions.

"What Vice Premier Wan Li said reflects the actual situation over recent years, and there is nothing new," according to the ministry statement.

What is new, according to foreign analysts here, is that Deng, who regularly appeared in public on the average of once every three days during recent months, has not been seen publicly or heard from since he met political Army commissars 32 days ago.

As the leading political figure in China after the death of party chairman Mao Tse-tung, Deng's imprimatur has been deemed essential to execute such controversial policy changes as normalization of Sino-American relations, peaceful overtures to Taiwan, gradual abolishing of communes and limited encouragement of free enterprise in the cities.

Despite his ability to promote proteges to top party and government posts during the past 18 months, Deng's active involvement in China's political life is still considered vital to preserve the nation's stability and carry out his reforms.

China's two other political powers, Chairman Hu Yaobang and Premier Zhao Ziyang--who with Deng are said to form a collective leadership--are not yet believed to have the influence to run the nation without their mentor's active support.

Diplomats in Peking say Deng is aware of his vital role as political linchpin and would never relinquish his power before the party puts a final stamp on his program and elects a new Central Committee at the party congress tentatively planned for next fall.

Analysts believe he has withdrawn from the public spotlight as a tactic to encourage other older officials to step down during the bureaucratic rectification drive expected to begin soon.

With reported plans to cut up to one third of the 600,000 central government employes, Peking is counting on massive retirements to meet its goal, according to analysts. The Hong Kong Communist newspaper Wen Hui Po, which frequently serves as a mouthpiece for the mainland government, said this week that Deng's disappearance is a "strategic arrangement" designed to conserve his strength and give his designated successors a chance to run national affairs.

"Deng Xiaoping's rest outside of Peking shows that the system of collective leadership has already gone into orbit," said the newspaper. "Although the veterans are not in Peking, they should not worry about every affair of state.

"The young and strong ones can handle them."