A Spanish government report released in Madrid yesterday placed most of the blame for the world's worst air disaster on the pilot of one of the two jumbo jets that collided on a foggy runway in the Canary Islands March 27, 1977, killing 583 people.

"The fundamental cause of this accident was the fact that the KLM (Royal Dutch Airlines) captain took off without clearance," the official investigating commission's report said.

The KLM Boeing 747 roared down the runway at Los Rodeos Airport on the island of Tenerife and hit a taxing Pan American Airlines 747. All 243 people on the KLM jet were killed, as were 335 on the Pan Am plane. There were 61 survivors.

The Dutch pilot, Jacob Louis Velthuyzen van Zauten, "did not obey the 'stand by for takeoff' from the tower, did not interrupt takeoff on learning that the Pan Am was still on the runway and in reply to the flight engineer's query as to whether the Pan Am had already left the runway, replied emphatically in the affirmative," the report said.

The report also said, according to wire service accounts, that a possible contributing factor was that "two important radio transmission - one from the power and the other from the Pan Am - took place at the same time."

The Washington Post first reported in April 1977 that the tower's radioed instructions to the Dutch captain to "standby for takeoff" were not heard in the Dutch cockpit, probably because of a simulataneous transmission from the Pan Am jet. It is unusual for the tower, a plane taxing and a plane taking off to be sharing the same frequency.

Both the Pan Am and KLM jets were at the Tenerife airport by chance. They had originally been scheduled to land at the better-equipped Las Palmas Airport on the Grand Canary Island, but a terrorists' explosion had closed the airport there. Both planes were charters, carrying vacationers. Almost all of the Pan Am's passengers came from southern California.

The report said that other contributing factors included "imperfect language" used in radio conversations between the control tower and the airliners; the Pan Am plane's not having left the runway by the correct taxi lane (a charge Pan Am has denied); low-lying clouds; unusual airport congestion becuase of the Las Palmas bombing, and a deadline closing in on the Dutch captain.

The Captain, under KLM's rules, was approaching the end of his allowable duty schedule, with weather closing in. American sources who have heard the recording from the Dutch cockpit have called the uncleared takeoff "a classic case of get-home-itis."

Charles F. Krause, a New York attorney who is chairman of the plaintiffs' committee in litigation against the airlines and the Spanish government, said yesterday that 89 cases of 644 filed remain to be settled. Most settlements - now totalling more than $50 million - have been out of court. The first jury award - to a widower - came last week and was $375,000.

KLM, Pan Am and Spain are sharing liability in the settlements, Krause said, although the exact division of responsibility is to be decided in court later.