The Soviet news agency Tass reported today that President Konstantin Chernenko had addressed a meeting of the ruling Politburo after an illness that has kept him from public view for almost six weeks.

An official government communique said that the 73-year-old Soviet leader had attended the regular session of the Politburo today and had addressed the ruling council on agricultural topics.

The pointed reference to Chernenko in today's communique issued by Tass appeared to be a clear effort to squelch widespread rumors that he was gravely ill and about to relinquish his post.

The routine report that is issued after meetings of the Politburo today included the following sentence:

"The reliable ensuring of the spring sowing campaign, as was stressed by Konstantin Chernenko speaking at the Political Bureau of the Communist Party Central Committee's meeting, becomes especially important this year."

In Washington, government analysts noted that Chernenko had used similar language at a Politburo meeting last November, and the wording of today's announcement left it unclear whether these were new remarks by Chernenko.

The analysts using this argument noted that the Russian language does not use definite articles, so in Russian the key word "meeting" could refer to today's meeting, or to an earlier session. In English, it could be translated as "a meeting" or as "the meeting," the latter implying today's session.

Chernenko was last seen in public on Dec. 27 at a Kremlin ceremony. He was hospitalized in early January with an unspecified ailment and his condition is believed to have become serious at one point. He was reported by Soviet officials to have recovered and to be convalescing at his dacha outside Moscow.

Tonight's statement followed a comment last night by the editor in chief of the Communist Party newspaper Pravda, Viktor Afanasiev, that Chernenko was ill. In a live interview with Italian state television, according to reports from Rome carried by western news agencies, Afanasiev said:

"I have to tell you that Comrade Chernenko is ill. I am not in a position to say what the gravity of his illness is as I am not a doctor. However, I know that he is still in charge of the party and the country despite being ill. We hope that this period will pass and will not be too long."

The statement by Afanasiev, who is a member of the Central Committee, was the first public confirmation of Chernenko's illness. Soviet officials have said as much in private after the postponement of a scheduled summit meeting of Warsaw Pact leaders last month.

Last Friday, the top Foreign Ministry spokesman, Vladimir Lomeiko, said the Soviet leader was taking a winter vacation near Moscow.

Chernenko is scheduled to make a major speech on Feb. 22, when he must address the voters of his district in the current campaign for election to the Supreme Soviet of the Russian Federation.