Canadian plane maker Bombardier said the 50-seat CRJ-100 regional jet in Sunday's crash in Lexington, Kentucky, was delivered new to Comair in 2001.

Bombardier, the world's third-largest civil aircraft maker, said the jet was delivered January 30 of that year.

Bombardier said it had not yet been provided with a tail number for the aircraft. Bombardier would not speculate on the cause of the crash but said it would be cooperating with the US Federal Aviation Administration and National Transportation Safety Board.

"We have a product safety team that will be dispatched to the scene and we will be assisting the FAA and NTSB in their investigations," said Bert Cruickshank, spokesman for Bombardier Aerospace.

The Kentucky crash appears to be the second-worst in terms of fatalities involving a Bombardier regional jet.

In November 2004, 47 passengers and six crew members died in the crash of a Bombardier regional jet flown by China Eastern Airlines in Baotou, in China's northern Inner Mongolia region. One person was killed on the ground.

Bombardier has delivered 1,360 regional jets since spearheading the development of the format in 1992. Over that time, it has delivered 226 units of the original CRJ-100 50-seat model and 709 of the comparable CRJ-200.

The Montreal-based manufacturer, which also makes business jets and has manufacturing facilities in the United States and Belfast, Northern Ireland, also makes 70-seat and 90-seat regional jets and turboprop aircraft.