On October 29, 1972, after further negotiations with Penn Central, Amtrak took over operation of the 600-series trains as "Silverliner Service", named for the Silverliner cars used to run the trains. Amtrak assumed formal responsibility for the "Silverliner Service" and "Clockers" around April 1974. Penn Central (and later Conrail and finally SEPTA Regional Rail) continued to operate Paoli–Philadelphia commuter service. Amtrak took over ticketing for the "Silverliner Service" and "Clockers" from Penn Central on July 1, 1975. On October 26, 1975, SEPTA funded an increase from 9 to 11 daily round trips. Amtrak began including a listing of connecting trains to/from New York City in the November 1975 timetable.