WASHINGTON (AP) _ The Federal Aviation Administration is being told that inadequate training and a shortage of controllers is contributing to an increasing number of near- collisions of aircraft both in the air and on the ground.

''The number of reported incidents, especially those involving controller errors, has increased significantly during the past three years,'' Jim Burnett, chairman of the National Transportation Safety Board, told a House investigations subcommittee Thursday.

Several committee members criticized senior FAA officials for not hiring more controllers, bending to pressure from the airlines to put more aircraft into the air and not adequately training controllers to deal with growing traffic requirements.

The exchange occurred amid disclosure by the NTSB that it is investigating two incidents that occurred this week - one in Chicago and another over New Jersey - involving near collisions of commercial aircraft.

The incident Tuesday at O'Hare International Airport in Chicago involved a Northwest Airlines jumbo jet, carrying 190 passengers and 18 crewmembers, and a United Airlines Boeing 727 with 108 people aboard.

According to the NTSB and FAA, Northwest Flight 3, bound for Tokyo, was in its takeoff roll when the pilot screeched to a halt after being told by the control tower than the United jetliner, Flight 229 bound for Denver, was on the same runway just ahead.

Burnett said the jumbo jet halted about 2,000 feet to 2,500 feet ahead of the United plane, but that its brakes were so hot it took 45 minutes for them to cool down. He said the NTSB was investigating the incident, but that preliminary indications were that the controllers were not at fault.

The United plane ''had never been cleared to actually get on the ruwnay and take off'' although the pilot had been told he could proceed across a taxiway to a point near the runway, FAA spokesman Fred Farrar said.

The NTSB, meanwhile, also was investigating an incident over New Jersey on Wednesday in which a Pan Am Express commuter plane had to take evasive action to avoid an Air Force cargo jet. A flight attendant and a passenger were injured.

Farrar said both aircraft were under the control of the military controllers at McGuire Air Force Base. The commuter landed safely in New York and the military jet at McGuire, according to FAA and Pentagon officials.

Burnett told the congressional panel Thursday that he is concerned the FAA may be allowing traffic increases even though the controller work force is short staffed and still relatively inexperienced.

A committee member, Rep. Guy Molinari, R-N.Y., accused the FAA of bending to the demands of the airlines by putting more planes in the air in efforts to reduce the number of delays. This is putting additional strains on the air traffic control system, he said.

Chicago's O'Hare airport has been the subject of special scrutiny after three near-collisions at the airport last year. In Wednesday's incident, the Northwest pilot was ordered to abort his takeoff after an extra controller in the tower, who was evaluating another controller, saw that both jets were on the same runway, according to Burnett.

There were different accounts as to how close the two aircraft came. Burnett and Farrar said the separation was reported at 2,000 feet to 2,500 feet, while a United spokesman, Joe Hopkins, said the planes came no closer than 4,250 feet.

Bob Gibbons, a spokesman for Northwest, said the Boeing 747 took off about an hour after the incident after the tires were cooled and checked and landed without incident in Tokyo.

Hopkins said United was cooperating with investigators, but the airline had no immediate comment on what might have caused the incident.

FAA Administrator Donald Engen told the House subcommittee that agency officials ''remain concerned ... about the threat of midair collisons'' as well as so-called ''runway incursions'' in which hazardous conditions develop at busy airports.

Last year, there were 866 reports of near-collisions in the air and another 497 incidents on airport runways and taxiways, both increases over previous years.

But an FAA spokesman, Stephen Hayes, said the number of runway incidents has declined in recent months.