The administration, not being happy with the situation, made full use of its federal rights to build its own line but it could not rely on financial aid from the Swiss Confederation, the authorities being vehemently opposed to any rival transit route.

Because of this, business circles in Paris were interested in co-financing a viable international transit route through Switzerland.

Construction began on 15 October 1906 but within months the Swiss federal authorities ordered the BLS to enlarge the tunnel to double track and to profile its access ramps to suit.

With the completion of the access ramps, the other civil engineering works on the line, 33 tunnels, 3 avalanche galleries and 22 bridges, together with the provision of electrical support masts, power stations, sub-stations, etc., the line, powered at 15,000 volts, alternating current, 16⅔ Hz was officially opened on 19 June 1913.

Freight traffic between Germany and Italy, which could be routed via the Lötschberg line meant that the company was able to offset the loss of transit via Delle.

At the end of 1993, the Swiss Confederation commissioned the BLS to provide a "piggyback" corridor along its line for road vehicles with a width of 2.5 m (98.4 in) and a corner height of 4 m (13 ft 1.5 in).

The construction work began in January 1994 and the opening was delayed, due to geological problems on the southern side of the Simplon, until 11 June 2001.

(Using EU legislation Britain's railway network can probably show best and worst what happened with its divisions and fragmentation).

The organisation was also changed, the company being now based around the three profit-focused core business of infrastructure, passenger traffic and cargo.

In voting "Yes" the Swiss people gave their approval for the construction of two transverse routes through the Alps, one at the Gotthard, the other at the Lötschberg.

The original NRLA Lötschberg project provided for two single bore tunnels between Frutigen and the Rhône valley, a distance of 41 km (25.5 mi).

For financial reasons the tunnel length was shortened to 34.6 km (21.5 mi), and the greater part of one of the bores was only constructed as a shell.

Since the completion of NRLA and the opening of the new Lötschberg Base Tunnel, the BLS is responsible for the operation of train services along the entire Lötschberg–Simplon route.

The directly owned main line of the Bern-Lötschberg-Simplon-Bahn ran from Thun, where it connected with the Swiss Federal Railways through Spiez and the Lötschberg Tunnel to Brig, where it connects with the Swiss Federal Railways owned Simplon Tunnel to Italy.

Between 2004 and 2006, when it was subsumed into the BLS AG, the company also operated extensive commuter services as part of the Bern S-Bahn network.