The new report also said there was “no evidence of technical or human error”.
Correspondents say this matches claims that MH17 was hit by missile shrapnel.
Investigators relied on cockpit data, air traffic control and images, as the crash site in eastern Ukraine remains too dangerous to access amid fighting between government troops and rebels.
The plane was flying from Amsterdam to Kuala Lumpur when it crashed in rebel-held territory in eastern Ukraine.
All 298 people on board, most of them from the Netherlands, died when the plane came down, amid reports it was shot down by pro-Russian rebels.
The report made no comment on who might have fired the missile.
Both sides in this conflict use the same weapon, reports the BBC’s transport correspondent Richard Westcott, and to find out who was responsible investigators would need to determine where the missile was launched.
One expert said they should eventually be able to work that out with a combination of radar data and evidence from the scene, our correspondent reports.
A sobering fact highlighted in this report was that three other, very large commercial airliners flew over the same area at around the same time, he adds.
The report from Dutch experts says the plane “broke up in the air probably as the result of structural damage caused by a large number of high-velocity objects that penetrated the aircraft from outside”.
The investigators have not visited the crash site because of fighting in the area but they said photographic evidence of the wreckage suggests the plane split into pieces during “an in-flight break up”.