[5] Regionalverkehr Oberaargau and two other companies merged in 1999 to form Aare Seeland mobil, who continues to own and operate the line.

[6] Between 2010 and 2012, Aare Seeland mobil built a 1.8-kilometre (1.1 mi) extension between Niederbipp and Oensingen, using a different alignment from the original routing.

[7][1] The line begins at Langenthal, where Aare Seeland mobil (ASm) has an island platform on the north side of the station.

From Niederbipp, the 2012 extension follows the right-of-way of the Jura Foot Line to Oensingen.

[9] As of the December 2021 timetable change,[update] Aare Seeland mobil operates half-hourly service over the line.