Amtrak has assumed full responsibility for maintenance of its Acela trains, ending its day-to-day relationship with a foreign consortium that built the railroad's sleek but troubled premium service.

The transfer of management and oversight from Montreal-based Bombardier. and French engineering group Alstom within the past couple of months is seven years earlier than originally planned, Amtrak said. Amtrak and Bombardier would not comment on the cost of the contract, which had included strict reliability terms for the high-speed trains. The manufacturers will still provide advice and parts, if needed,

Amtrak and Bombardier said. Transfer of maintenance stemmed from an agreement between Amtrak and the consortium in 2004 that settled a legal fight involving Acela's production and delivery snags and early service setbacks. Acela began service in 2000.