sentences:  Anticipating further aging in its rolling stock, RATP changed its policy regarding replacement of rolling stock to avoid a massive, simultaneous replacement of all rolling stock.September 28, 1990 marked the approval of the contract to manufacture the MP 89 trains by RATP for an order of 665 cars, with GEC- Alsthom being selected as the manufacturer.In 1994, a prototype MP 89 CA was built for testing at a facility near the "Petite Ceinture", the former rail line that encircled Paris.