A Chinese official was quoted in a Yugoslav newspaper today as saying that the Soviet Union has broken off trade negotiations with China in retaliation for China's invasion of Vietnam.

The Belgrade daily Politika, in a dispatch from its Peking correspondent, quoted a "very competent Chinese official" as the source for the report about suspension of the talks, which reportedly had been under way in Moscow.

According to the Politika dispatch, official Soviet sources contacted in Peking were unable to confirm the Chinese claim that trade negotiations had been suspended. But they were quoted as saying that during the latest round China had included a request for all-purpose M16 and M18 helicopters which could also be used for the destruction of tanks -- a sale which had to be reconsidered following the invasion of Vietnam.

The Soviet sources estimated bilateral trade between China and the Soviet Union as amounting to $320 million last year, adding that the Chinese also wanted to buy generators and equipment for hydroelectric power stations.

Politika also quoted a well-informed Chinese official as saying that Vietnamese advisers were present both in the Laotian government and the Central Committee. He also alleged that three to four Vietnamese divisions were now in Laos considerably outnumbering the Laotian Army.

Earlier this week, Politika reported Chinese claims that Vietnam is unable to launch a counteroffensive because of a dire shortage of fuel oil. Its Peking correspondent and other Yugoslav journalists in China are known to enjoy privileged access to Chinese officials.

The suspension of Soviet-Chinese trade talks could not be confirmed in Moscow. The two countries conduct annual negotiations on bilateral trade at the deputy foreign trade minister level.

Western analysts in Hong Kong said they had not heard of a break in the talks but were not surprised that the Soviets had shown displeasure at the Chinese invasion of Vietnam in this way, Washington Post correspondent Jay Mathews reported.

[They said that trade talks for purchase of such equipment from Moscow are held annually at about this time, but that the Chinese would probably have little trouble buying similar equipment from Western sources if rejected by the Soviets.]

According to Soviet figures, bilateral trade turnover figures have fluctuated from $230 million in 1975 to $350 million in 1976. The Soviets over the past few years have imported more goods from China than they exported.