Federal investigators say Connex engineer Robert Sanchez was text messaging on his cell phone right before he ran a red light and collided with a freight train, killing 25 people.
Metrolink made allegations of poor oversight against Connex in connection with the accident on September 12, 2008. Metrolink board member Richard Katz said he believes Connex "has a different view of public safety than we do" and that Metrolink should consider a change.
The contractor accused Metrolink of finger-pointing and sent a formal notice of its plans for separation. Connex has defended its safety record, saying a field testing program exceeds industry standards.
City News Service contributed to this report.