Publisher John P. McGoff agreed yesterday to drop his $43 million antitrust suit against the Sacramento Bee, just minutes before he was to be asked under oath whether the South African government financed his purchase of the rival Sacramento Union in 1974.

McGoff's attorney, E. Craig Moody, said in federal court in San Francisco on July 30 that McGoff would invoke his Fifth Amendment protection against self-incrimination rather than answer the question.

The agreement to settle the civil suit and a countersuit was reached by McGoff and C. K. McClatchy, eidtor of McClatchy Newspapers, which owns the Sacramento Bee, it was announced in San Francisco.

An investigating commission appointed by the South African government determined June 3 that McGoff received more than $10 million from a secret South African propaganda fund to purchase The Washington Star. When that deal fell through, the commission said, McGoff used more than $6 million of the money to finance his purchase of the Union.

In an open letter published July 18 in more than 40 newspapers he owns or controls, McGoff denied being an agent of the South African government and denied that South Africa had any ownership interest in the Union.

However, McGoff did not deny the findings of the Erasmus Commission, an official body of the South African government, that the government of now-deposed prime minister John Vorster financed McGoff's purchase of the Union.

Mc Goff and Detroit attorney Richard Jones, who is a principal in some McGoff papers, had been ordered by U.S. District Court 4udge Charles Renfrew to testify about the source of funds used to buy the Union. Renfrew fined one of McGoff's companies and Jones' Detroit law firm $10,000 each for failing to appear and testify on the issue. McClatchy said he believes McGoff and Jones will now ask Renfrew to cancel the fines.