The Seeländische Lokalbahnen was renamed the Biel-Täuffelen-Ins Railway (German: Biel-Täuffelen-Ins-Bahn, BTI) as of 1 September 1945.

This allowed the dismantling of the line that had run along streets under the large SBB railway bridge to Biel station forecourt.

An early indication of the later merger was a formal agreement that was contracted on 5 April 1984 between the BTI, the OJB, the SNB, the Oberaargauischen Automobilkurse (a bus company; OAK), the Ligerz-Tessenberg-Bahn (a funicular railway; LTB) and the Bielersee-Schiffahrts-Gesellschaft (Lake Biel Ferry Company; BSG) under the name of Oberaargau-Solothurn-Seeland-Transport (OSST).

The majority of the participants of Oberaargau-Solothurn-Seeland-Transport were merged to form Aare Seeland mobil (ASm) in 1999.

Thus, the most important development areas (living, work, leisure) of the region would be connected without the need to change trains.