* Deutsche Bahn suing Bombardier for $454 million
* Bombardier says S-Bahn warranty ended in 2007
* Bombardier says open to dialogue with Deutsche Bahn
TORONTO, March 4 (Reuters) - Bombardier Inc, the world's biggest train maker, on Monday said it rejected claims in a lawsuit by German rail operator Deutsche Bahn AG over problems with its S-Bahn rail line in Berlin.
Deutsche Bahn is suing Bombardier for 350 million euros ($454 million) in damages, alleging "serious defects" with brakes and engines, following a series of breakdowns since 2009. The lawsuit comes after an out-of-court agreement between the two companies broke down.
Canada's Bombardier said the claims regarding the Class 481 trains used on the S-Bahn line are without merit and the allegations are defamatory.
The general warranty for the S-Bahn trains ended in 2007 by mutual agreement, Bombardier said. S-Bahn Berlin, a subsidiary of Deutsche Bahn, has been responsible for the trains' maintenance from the start and Bombardier has no contractual obligations for maintenance and repair of the 481 series.
"Prolonged litigation is not in the interests of either company," Bombardier said, adding that it remains open to dialogue.
Deutsche Bahn is suing Bombardier separately for an additional 160 million euros over issues with other trains.
Bombardier's shares were down 2 Canadian cents at C$4.09 on the Toronto Stock Exchange in early trading.