Malaysia Airlines' senior vice-president Europe, Huib Gorter, said the flight route had been declared safe by the authorities, was being used by many other airlines and was not subject to any restrictions.
Although the area where the jet crashed had a no-fly zone in place up to 9,754m (32,000ft), the airliner was flying above the limit at 10,058m (33,000ft).
The UK's Civil Aviation Authority says airlines' decisions on whether to fly over conflict zones will be based on a range of factors - advice from the Foreign Office, warnings in the area, weather, navigation aids, strikes and which airports are out of action.
In the 48 hours running up to the MH17 crash, many airlines had chosen to keep flying in the area, as data from flight tracker Planefinder shows.