Sudan, reacting to Ethiopian protests and concerned that other Arab countries would complain, yesterday canceled its cooperation with an Israeli-organized airlift bringing thousands of Jews out of Ethiopia, diplomatic sources said last night.

The sources said the Sudanese action "kills this program dead as a doornail," leaving approximately 6,000 Falashas, or Ethiopian Jews, with little hope of escaping that famine-ravaged country.

The sources said Sudan notified the United States yesterday that publicity about the airlift meant that it could no longer cooperate in the program, in which Ethiopian Jews were flown almost daily from the Sudanese capital of Khartoum to European cities. From there, they went on to Israel.

The United States is known to have played a major behind-the-scenes role in obtaining Sudanese cooperation despite the fact that Sudan, as an Arab country, does not recognize Israel and considers itself in a state of belligerency with the Jewish state.

U.S. officials refused to comment last night about U.S. involvement in the program or about communication between Washington and the Sudanese government.

However, in a further indication that the program has been derailed, Trans European Airways, a Belgian charter airline that has been making the flights from Sudan, announced yesterday that it would no longer participate.

Press reports began circulating last month, and more frequently in the last few days, that the Israeli government was trying to bring the Falashas out in large numbers. The reports, including the first public disclosures in Israel of the airlift, have said that between 10,000 and 20,000 Falashas have been airlifted or were awaiting transport.

Since the military ouster of the late emperor Haile Selassie in September 1974, the Israeli government has been smuggling Falashas out of Ethiopia.

They are settled in a region around Gondar that has been particularly hard hit by civil war and famine, factors that have increased sympathy in Israel for their plight and led to the recent large-scale effort to get them out.

According to the sources, the United States, which has close aid ties to Sudanese President Jafaar Nimeri, readily cooperated in persuading Sudan to permit the airlift. The sources said the Sudanese, aware that the exercise could subject them to severe criticism in the Arab world, had insisted on maximum secrecy and set the condition that the Falashas moving through its territory be taken to Europe rather than directly to Israel.

After reports about the magnitude of the airlift appeared last week, Ethiopia's radical leftist government denounced it as a "sinister operation" and said it would protest to Sudan about "gross interference" in its internal affairs.

The Falashas, who legends say are descended from King Solomon and the Queen of Sheba, are a poverty-stricken group. They are mostly potters by trade and have lived for centuries in isolated villages.

Their plight has been a source of contention for years in Israel, where many contend that the Falashas are not Jews and not entitled to settle in the Jewish state under its "law of the return."

However, the Israeli government has been under pressure from Israeli and U.S. sympathizers of the Falashas to do something for the group, whose plight has been worsened by the famine in eastern Africa and the civil war in the outlying regions of Ethiopia.