Soviet President Konstantin Chernenko was absent today as other members of the Kremlin leadership braved the bitter cold to pay last respects to the late marshal Dmitri Ustinov at a solemn Red Square funeral.

With the temperature 7 below zero in downtown Moscow, Chernenko, who at 73 suffers from respiratory problems, probably was advised to miss the hour-long outdoor ceremony, diplomatic observers speculated.

The sky was clear, but a frost tinged the air as the procession began from the House of Unions, carrying the ashes of Ustinov, who was minister of defense and one of the most powerful members of the Politburo when he died Thursday at 76. The urn was buried in the Kremlin wall, next to other Soviet dignitaries.

Politburo member Grigori Romanov, as chairman of the funeral commission, gave the opening speech. He was followed by Marshal Sergei Sokolov, 73, the military professional picked Saturday to replace Ustinov at the Defense Ministry.

They and other speakers praised Ustinov as a "tireless fighter for the cause of socialism," for his role in defending the nation during World War II and for "increasing the might of the Soviet Army and Navy" in the postwar years.

Ustinov, defense minister since 1976, began his political career as Joseph Stalin's commissar for armaments in 1941 and for many years headed the Soviet Union's defense industries.

Chernenko's absence was not mentioned in the official press, but two speakers, including Sokolov, made a pointed reference to Chernenko as head of the Politburo, as if to reassure the Red Square crowd and television viewers nationwide about the unusual gap in the lineup atop the Lenin Mausoleum.

Attendance at funerals -- like observance of important holidays -- is usually a required function for the Soviet leadership. When Ustinov failed to show up to take the military salute at the Nov. 7 national day parade this year, it was the first sign that his health was failing.

Then, fellow Politburo member Victor Grishin explained that the defense minister had a cold. Today, a Foreign Ministry official also suggested that Chernenko "probably had a cold."

But western diplomats said they felt it more likely that Chernenko's absence was precautionary, given the severity of the weather. On Saturday, he had led the Politburo in paying respects at Ustinov's bier in the House of Unions.

Chernenko reportedly suffers from emphysema. He walks slowly and, in his speeches, has shown a marked shortness of breath. Kremlin advisers may have been mindful of the sequence of events two years ago, when then-president Leonid Brezhnev died three days after presiding over the long Nov. 7 celebration.

Today, other members of the Politburo -- including five in their seventies -- wore heavy coats and fur hats as they took their traditional place atop the mausoleum. Premier Nikolai Tikhonov, 79, stood at the center, with Romanov to his left. At his right were Foreign Minister Andrei Gromyko, then Mikhail Gorbachev, the second-ranking official in the Communist Party hierarchy, who cut short a trip to Britain after Ustinov's death.

Of the leaders, Gromyko, 75, alone stood stock still, as the others shifted their feet to combat the cold.

The ceremony was held with full pomp and solemnity. A military band played Chopin's Funeral March, and black-draped battle standards were dipped in mourning. A crowd of workers filled half of Red Square, some bearing standards with Ustinov's portrait framed in red and black.

Heading the procession as it slowly entered Red Square were officers carrying Ustinov's portrait and red cushions bearing his medals and awards. Behind them came 20 rows of soldiers bearing man-sized wreaths. The urn rested on a gun carriage pulled by an armored personnel carrier and was followd by members of Ustinov's family, ranking officers and members of the leadership.

The speeches -- including an unusual oration by a foreigner, Bulgarian Defense Minister Dobri Dzhurov -- lasted only 30 minutes. They were followed by a brief ceremony at the Kremlin wall, behind the mausoleum, where Romanov laid the urn in the wall.

By the time the ceremony concluded with a brief military parade, the chill had taken its toll on the crowd. Mustaches were covered with white frost, cheeks had turned bright pink and mourners, including officers of the Soviet Army, were discreetly jumping from foot to foot.