MINNEAPOLIS (AP) _ Nine hours before two jumbo jets nearly collided at snowy Minneapolis-St. Paul International Airport, two other jets came within three-fourths of a mile of each other on the same runway, authorities said.

The incident Sunday, involving Eastern and Republic airlines' DC9s, was revealed during an investigation of the near-collision of Northwest Airlines jets later that day, the Federal Aviation Administration said Friday.

The air traffic controller involved in the Eastern-Republic ''operational error,'' has been decertified and cannot control air traffic until preliminary findings are released and he is retrained, said FAA spokesman Fred Farrar.

Two controllers were decertified after the two Northwest DC10s, carrying more than 500 people, missed each other by about 100 feet Sunday evening.

Ed Pinto, a spokesman for the FAA in Washington, D.C., said the Republic and Eastern jets came within 4,000 feet of each other on the ground about 12:15 p.m. Sunday, during a snowstorm that dumped 15 inches of slushy snow.

Pinto said a Republic Airlines jet from Chicago landed on a runway already occupied by an Eastern Airlines jet that had experienced a power loss in one of its two engines and had to abort its takeoff for Atlanta.

The distance between the two planes closed to about 4,000 feet before the Republic jet turned off on a taxiway, Farrar said. FAA rules in such situations call for a minimum separation of at least 6,000 feet.

The FAA hadn't determined Friday night whether the Republic pilots knew the Eastern jet was on the runway, Farrar said.

''Republic was landing and made a very safe landing,'' said Mort Edelstein, an FAA spokesman in Chicago. ''They had plenty of runway so there was no life- threatening situation.''

National Transportation Safety Board spokesman Bob Buckhorn said the board is investigating the possibility that the Eastern jet's engine was extinguished by snow and slush.The runway was closed for snow removal after the incident.

About nine hours later, the pilot of a Northwest DC-10 was forced to gun his engines and make an early takeoff to avoid hitting a second Northwest DC- 10 that had crossed its path on the runway, said NTSB Chairman James Burnett, who came to Minneapolis to investigate the incident. The jet taking off missed the other one by about 100 feet, Burnett said.

The pilot could not brake because of snow on the runway.

Burnett said the NTSB will be looking at Sunday's workload for the controllers, who had to manage large volumes of aircraft as well as monitor snowplow crews working to keep the airport open.

A report is expected in about two months, he said.